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<!DOCTYPE html>
<html lang="en" class="RFC">
<head>
<meta charset="utf-8">
<meta content="Common,Latin" name="scripts">
<meta content="initial-scale=1.0" name="viewport">
<title>RFC 8746: Concise Binary Object Representation (CBOR) Tags for Typed Arrays</title>
<meta content="Carsten Bormann" name="author">
<meta content="
       The Concise Binary Object Representation (CBOR), as defined in RFC
      7049, is a data format whose design goals include the possibility of
      extremely small code size, fairly small message size, and extensibility
      without the need for version negotiation. 
       This document makes use of this extensibility to define a number of
      CBOR tags for typed arrays of numeric data, as well as additional
      tags for multi-dimensional and homogeneous arrays.  It is intended as
      the reference document for the IANA registration of the CBOR tags
      defined. 
    " name="description">
<meta content="xml2rfc 2.40.1" name="generator">
<meta content="binary format" name="keyword">
<meta content="data interchange format" name="keyword">
<meta content="JSON" name="keyword">
<meta content="8746" name="rfc.number">
<link href="rfc8746.xml" rel="alternate" type="application/rfc+xml">
<link href="#copyright" rel="license">
<style type="text/css">/*

  NOTE: Changes at the bottom of this file overrides some earlier settings.

  Once the style has stabilized and has been adopted as an official RFC style,
  this can be consolidated so that style settings occur only in one place, but
  for now the contents of this file consists first of the initial CSS work as
  provided to the RFC Formatter (xml2rfc) work, followed by itemized and
  commented changes found necssary during the development of the v3
  formatters.

*/

/* fonts */
@import url('https://fonts.googleapis.com/css?family=Noto+Sans'); /* Sans-serif */
@import url('https://fonts.googleapis.com/css?family=Noto+Serif'); /* Serif (print) */
@import url('https://fonts.googleapis.com/css?family=Roboto+Mono'); /* Monospace */

@viewport {
  zoom: 1.0;
  width: extend-to-zoom;
}
@-ms-viewport {
  width: extend-to-zoom;
  zoom: 1.0;
}
/* general and mobile first */
html {
}
body {
  max-width: 90%;
  margin: 1.5em auto;
  color: #222;
  background-color: #fff;
  font-size: 14px;
  font-family: 'Noto Sans', Arial, Helvetica, sans-serif;
  line-height: 1.6;
  scroll-behavior: smooth;
}
.ears {
  display: none;
}

/* headings */
#title, h1, h2, h3, h4, h5, h6 {
  margin: 1em 0 0.5em;
  font-weight: bold;
  line-height: 1.3;
}
#title {
  clear: both;
  border-bottom: 1px solid #ddd;
  margin: 0 0 0.5em 0;
  padding: 1em 0 0.5em;
}
.author {
  padding-bottom: 4px;
}
h1 {
  font-size: 26px;
  margin: 1em 0;
}
h2 {
  font-size: 22px;
  margin-top: -20px;  /* provide offset for in-page anchors */
  padding-top: 33px;
}
h3 {
  font-size: 18px;
  margin-top: -36px;  /* provide offset for in-page anchors */
  padding-top: 42px;
}
h4 {
  font-size: 16px;
  margin-top: -36px;  /* provide offset for in-page anchors */
  padding-top: 42px;
}
h5, h6 {
  font-size: 14px;
}
#n-copyright-notice {
  border-bottom: 1px solid #ddd;
  padding-bottom: 1em;
  margin-bottom: 1em;
}
/* general structure */
p {
  padding: 0;
  margin: 0 0 1em 0;
  text-align: left;
}
div, span {
  position: relative;
}
div {
  margin: 0;
}
.alignRight.art-text {
  background-color: #f9f9f9;
  border: 1px solid #eee;
  border-radius: 3px;
  padding: 1em 1em 0;
  margin-bottom: 1.5em;
}
.alignRight.art-text pre {
  padding: 0;
}
.alignRight {
  margin: 1em 0;
}
.alignRight > *:first-child {
  border: none;
  margin: 0;
  float: right;
  clear: both;
}
.alignRight > *:nth-child(2) {
  clear: both;
  display: block;
  border: none;
}
svg {
  display: block;
}
.alignCenter.art-text {
  background-color: #f9f9f9;
  border: 1px solid #eee;
  border-radius: 3px;
  padding: 1em 1em 0;
  margin-bottom: 1.5em;
}
.alignCenter.art-text pre {
  padding: 0;
}
.alignCenter {
  margin: 1em 0;
}
.alignCenter > *:first-child {
  border: none;
  /* this isn't optimal, but it's an existence proof.  PrinceXML doesn't
     support flexbox yet.
  */
  display: table;
  margin: 0 auto;
}

/* lists */
ol, ul {
  padding: 0;
  margin: 0 0 1em 2em;
}
ol ol, ul ul, ol ul, ul ol {
  margin-left: 1em;
}
li {
  margin: 0 0 0.25em 0;
}
.ulCompact li {
  margin: 0;
}
ul.empty, .ulEmpty {
  list-style-type: none;
}
ul.empty li, .ulEmpty li {
  margin-top: 0.5em;
}
ul.compact, .ulCompact,
ol.compact, .olCompact {
  line-height: 100%;
  margin: 0 0 0 2em;
}

/* definition lists */
dl {
}
dl > dt {
  float: left;
  margin-right: 1em;
}
/* 
dl.nohang > dt {
  float: none;
}
*/
dl > dd {
  margin-bottom: .8em;
  min-height: 1.3em;
}
dl.compact > dd, .dlCompact > dd {
  margin-bottom: 0em;
}
dl > dd > dl {
  margin-top: 0.5em;
  margin-bottom: 0em;
}

/* links */
a {
  text-decoration: none;
}
a[href] {
  color: #22e; /* Arlen: WCAG 2019 */
}
a[href]:hover {
  background-color: #f2f2f2;
}
figcaption a[href],
a[href].selfRef {
  color: #222;
}
/* XXX probably not this:
a.selfRef:hover {
  background-color: transparent;
  cursor: default;
} */

/* Figures */
tt, code, pre, code {
  background-color: #f9f9f9;
  font-family: 'Roboto Mono', monospace;
}
pre {
  border: 1px solid #eee;
  margin: 0;
  padding: 1em;
}
img {
  max-width: 100%;
}
figure {
  margin: 0;
}
figure blockquote {
  margin: 0.8em 0.4em 0.4em;
}
figcaption {
  font-style: italic;
  margin: 0 0 1em 0;
}
@media screen {
  pre {
    overflow-x: auto;
    max-width: 100%;
    max-width: calc(100% - 22px);
  }
}

/* aside, blockquote */
aside, blockquote {
  margin-left: 0;
  padding: 1.2em 2em;
}
blockquote {
  background-color: #f9f9f9;
  color: #111; /* Arlen: WCAG 2019 */
  border: 1px solid #ddd;
  border-radius: 3px;
  margin: 1em 0;
}
cite {
  display: block;
  text-align: right;
  font-style: italic;
}

/* tables */
table {
  width: 100%;
  margin: 0 0 1em;
  border-collapse: collapse;
  border: 1px solid #eee;
}
th, td {
  text-align: left;
  vertical-align: top;
  padding: 0.5em 0.75em;
}
th {
  text-align: left;
  background-color: #e9e9e9;
}
tr:nth-child(2n+1) > td {
  background-color: #f5f5f5;
}
table caption {
  font-style: italic;
  margin: 0;
  padding: 0;
  text-align: left;
}
table p {
  /* XXX to avoid bottom margin on table row signifiers. If paragraphs should
     be allowed within tables more generally, it would be far better to select on a class. */
  margin: 0;
}

/* pilcrow */
a.pilcrow {
  color: #666; /* Arlen: AHDJ 2019 */
  text-decoration: none;
  visibility: hidden;
  user-select: none;
  -ms-user-select: none;
  -o-user-select:none;
  -moz-user-select: none;
  -khtml-user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
}
@media screen {
  aside:hover > a.pilcrow,
  p:hover > a.pilcrow,
  blockquote:hover > a.pilcrow,
  div:hover > a.pilcrow,
  li:hover > a.pilcrow,
  pre:hover > a.pilcrow {
    visibility: visible;
  }
  a.pilcrow:hover {
    background-color: transparent;
  }
}

/* misc */
hr {
  border: 0;
  border-top: 1px solid #eee;
}
.bcp14 {
  font-variant: small-caps;
}

.role {
  font-variant: all-small-caps;
}

/* info block */
#identifiers {
  margin: 0;
  font-size: 0.9em;
}
#identifiers dt {
  width: 3em;
  clear: left;
}
#identifiers dd {
  float: left;
  margin-bottom: 0;
}
#identifiers .authors .author {
  display: inline-block;
  margin-right: 1.5em;
}
#identifiers .authors .org {
  font-style: italic;
}

/* The prepared/rendered info at the very bottom of the page */
.docInfo {
  color: #666; /* Arlen: WCAG 2019 */
  font-size: 0.9em;
  font-style: italic;
  margin-top: 2em;
}
.docInfo .prepared {
  float: left;
}
.docInfo .prepared {
  float: right;
}

/* table of contents */
#toc  {
  padding: 0.75em 0 2em 0;
  margin-bottom: 1em;
}
nav.toc ul {
  margin: 0 0.5em 0 0;
  padding: 0;
  list-style: none;
}
nav.toc li {
  line-height: 1.3em;
  margin: 0.75em 0;
  padding-left: 1.2em;
  text-indent: -1.2em;
}
/* references */
.references dt {
  text-align: right;
  font-weight: bold;
  min-width: 7em;
}
.references dd {
  margin-left: 8em;
  overflow: auto;
}

.refInstance {
  margin-bottom: 1.25em;
}

.references .ascii {
  margin-bottom: 0.25em;
}

/* index */
.index ul {
  margin: 0 0 0 1em;
  padding: 0;
  list-style: none;
}
.index ul ul {
  margin: 0;
}
.index li {
  margin: 0;
  text-indent: -2em;
  padding-left: 2em;
  padding-bottom: 5px;
}
.indexIndex {
  margin: 0.5em 0 1em;
}
.index a {
  font-weight: 700;
}
/* make the index two-column on all but the smallest screens */
@media (min-width: 600px) {
  .index ul {
    -moz-column-count: 2;
    -moz-column-gap: 20px;
  }
  .index ul ul {
    -moz-column-count: 1;
    -moz-column-gap: 0;
  }
}

/* authors */
address.vcard {
  font-style: normal;
  margin: 1em 0;
}

address.vcard .nameRole {
  font-weight: 700;
  margin-left: 0;
}
address.vcard .label {
  font-family: "Noto Sans",Arial,Helvetica,sans-serif;
  margin: 0.5em 0;
}
address.vcard .type {
  display: none;
}
.alternative-contact {
  margin: 1.5em 0 1em;
}
hr.addr {
  border-top: 1px dashed;
  margin: 0;
  color: #ddd;
  max-width: calc(100% - 16px);
}

/* temporary notes */
.rfcEditorRemove::before {
  position: absolute;
  top: 0.2em;
  right: 0.2em;
  padding: 0.2em;
  content: "The RFC Editor will remove this note";
  color: #9e2a00; /* Arlen: WCAG 2019 */
  background-color: #ffd; /* Arlen: WCAG 2019 */
}
.rfcEditorRemove {
  position: relative;
  padding-top: 1.8em;
  background-color: #ffd; /* Arlen: WCAG 2019 */
  border-radius: 3px;
}
.cref {
  background-color: #ffd; /* Arlen: WCAG 2019 */
  padding: 2px 4px;
}
.crefSource {
  font-style: italic;
}
/* alternative layout for smaller screens */
@media screen and (max-width: 1023px) {
  body {
    padding-top: 2em;
  }
  #title {
    padding: 1em 0;
  }
  h1 {
    font-size: 24px;
  }
  h2 {
    font-size: 20px;
    margin-top: -18px;  /* provide offset for in-page anchors */
    padding-top: 38px;
  }
  #identifiers dd {
    max-width: 60%;
  }
  #toc {
    position: fixed;
    z-index: 2;
    top: 0;
    right: 0;
    padding: 0;
    margin: 0;
    background-color: inherit;
    border-bottom: 1px solid #ccc;
  }
  #toc h2 {
    margin: -1px 0 0 0;
    padding: 4px 0 4px 6px;
    padding-right: 1em;
    min-width: 190px;
    font-size: 1.1em;
    text-align: right;
    background-color: #444;
    color: white;
    cursor: pointer;
  }
  #toc h2::before { /* css hamburger */
    float: right;
    position: relative;
    width: 1em;
    height: 1px;
    left: -164px;
    margin: 6px 0 0 0;
    background: white none repeat scroll 0 0;
    box-shadow: 0 4px 0 0 white, 0 8px 0 0 white;
    content: "";
  }
  #toc nav {
    display: none;
    padding: 0.5em 1em 1em;
    overflow: auto;
    height: calc(100vh - 48px);
    border-left: 1px solid #ddd;
  }
}

/* alternative layout for wide screens */
@media screen and (min-width: 1024px) {
  body {
    max-width: 724px;
    margin: 42px auto;
    padding-left: 1.5em;
    padding-right: 29em;
  }
  #toc {
    position: fixed;
    top: 42px;
    right: 42px;
    width: 25%;
    margin: 0;
    padding: 0 1em;
    z-index: 1;
  }
  #toc h2 {
    border-top: none;
    border-bottom: 1px solid #ddd;
    font-size: 1em;
    font-weight: normal;
    margin: 0;
    padding: 0.25em 1em 1em 0;
  }
  #toc nav {
    display: block;
    height: calc(90vh - 84px);
    bottom: 0;
    padding: 0.5em 0 0;
    overflow: auto;
  }
  img { /* future proofing */
    max-width: 100%;
    height: auto;
  }
}

/* pagination */
@media print {
  body {

    width: 100%;
  }
  p {
    orphans: 3;
    widows: 3;
  }
  #n-copyright-notice {
    border-bottom: none;
  }
  #toc, #n-introduction {
    page-break-before: always;
  }
  #toc {
    border-top: none;
    padding-top: 0;
  }
  figure, pre {
    page-break-inside: avoid;
  }
  figure {
    overflow: scroll;
  }
  h1, h2, h3, h4, h5, h6 {
    page-break-after: avoid;
  }
  h2+*, h3+*, h4+*, h5+*, h6+* {
    page-break-before: avoid;
  }
  pre {
    white-space: pre-wrap;
    word-wrap: break-word;
    font-size: 10pt;
  }
  table {
    border: 1px solid #ddd;
  }
  td {
    border-top: 1px solid #ddd;
  }
}

/* This is commented out here, as the string-set: doesn't
   pass W3C validation currently */
/*
.ears thead .left {
  string-set: ears-top-left content();
}

.ears thead .center {
  string-set: ears-top-center content();
}

.ears thead .right {
  string-set: ears-top-right content();
}

.ears tfoot .left {
  string-set: ears-bottom-left content();
}

.ears tfoot .center {
  string-set: ears-bottom-center content();
}

.ears tfoot .right {
  string-set: ears-bottom-right content();
}
*/

@page :first {
  padding-top: 0;
  @top-left {
    content: normal;
    border: none;
  }
  @top-center {
    content: normal;
    border: none;
  }
  @top-right {
    content: normal;
    border: none;
  }
}

@page {
  size: A4;
  margin-bottom: 45mm;
  padding-top: 20px;
  /* The follwing is commented out here, but set appropriately by in code, as
     the content depends on the document */
  /*
  @top-left {
    content: 'Internet-Draft';
    vertical-align: bottom;
    border-bottom: solid 1px #ccc;
  }
  @top-left {
    content: string(ears-top-left);
    vertical-align: bottom;
    border-bottom: solid 1px #ccc;
  }
  @top-center {
    content: string(ears-top-center);
    vertical-align: bottom;
    border-bottom: solid 1px #ccc;
  }
  @top-right {
    content: string(ears-top-right);
    vertical-align: bottom;
    border-bottom: solid 1px #ccc;
  }
  @bottom-left {
    content: string(ears-bottom-left);
    vertical-align: top;
    border-top: solid 1px #ccc;
  }
  @bottom-center {
    content: string(ears-bottom-center);
    vertical-align: top;
    border-top: solid 1px #ccc;
  }
  @bottom-right {
      content: '[Page ' counter(page) ']';
      vertical-align: top;
      border-top: solid 1px #ccc;
  }
  */

}

/* Changes introduced to fix issues found during implementation */
/* Make sure links are clickable even if overlapped by following H* */
a {
  z-index: 2;
}
/* Separate body from document info even without intervening H1 */
section {
  clear: both;
}


/* Top align author divs, to avoid names without organization dropping level with org names */
.author {
  vertical-align: top;
}

/* Leave room in document info to show Internet-Draft on one line */
#identifiers dt {
  width: 8em;
}

/* Don't waste quite as much whitespace between label and value in doc info */
#identifiers dd {
  margin-left: 1em;
}

/* Give floating toc a background color (needed when it's a div inside section */
#toc {
  background-color: white;
}

/* Make the collapsed ToC header render white on gray also when it's a link */
@media screen and (max-width: 1023px) {
  #toc h2 a,
  #toc h2 a:link,
  #toc h2 a:focus,
  #toc h2 a:hover,
  #toc a.toplink,
  #toc a.toplink:hover {
    color: white;
    background-color: #444;
    text-decoration: none;
  }
}

/* Give the bottom of the ToC some whitespace */
@media screen and (min-width: 1024px) {
  #toc {
    padding: 0 0 1em 1em;
  }
}

/* Style section numbers with more space between number and title */
.section-number {
  padding-right: 0.5em;
}

/* prevent monospace from becoming overly large */
tt, code, pre, code {
  font-size: 95%;
}

/* Fix the height/width aspect for ascii art*/
pre.sourcecode,
.art-text pre {
  line-height: 1.12;
}


/* Add styling for a link in the ToC that points to the top of the document */
a.toplink {
  float: right;
  margin-right: 0.5em;
}

/* Fix the dl styling to match the RFC 7992 attributes */
dl > dt,
dl.dlParallel > dt {
  float: left;
  margin-right: 1em;
}
dl.dlNewline > dt {
  float: none;
}

/* Provide styling for table cell text alignment */
table td.text-left,
table th.text-left {
  text-align: left;
}
table td.text-center,
table th.text-center {
  text-align: center;
}
table td.text-right,
table th.text-right {
  text-align: right;
}

/* Make the alternative author contact informatio look less like just another
   author, and group it closer with the primary author contact information */
.alternative-contact {
  margin: 0.5em 0 0.25em 0;
}
address .non-ascii {
  margin: 0 0 0 2em;
}

/* With it being possible to set tables with alignment
  left, center, and right, { width: 100%; } does not make sense */
table {
  width: auto;
}

/* Avoid reference text that sits in a block with very wide left margin,
   because of a long floating dt label.*/
.references dd {
  overflow: visible;
}

/* Control caption placement */
caption {
  caption-side: bottom;
}

/* Limit the width of the author address vcard, so names in right-to-left
   script don't end up on the other side of the page. */

address.vcard {
  max-width: 30em;
  margin-right: auto;
}

/* For address alignment dependent on LTR or RTL scripts */
address div.left {
  text-align: left;
}
address div.right {
  text-align: right;
}

/* Provide table alignment support.  We can't use the alignX classes above
   since they do unwanted things with caption and other styling. */
table.right {
 margin-left: auto;
 margin-right: 0;
}
table.center {
 margin-left: auto;
 margin-right: auto;
}
table.left {
 margin-left: 0;
 margin-right: auto;
}

/* Give the table caption label the same styling as the figcaption */
caption a[href] {
  color: #222;
}

@media print {
  .toplink {
    display: none;
  }

  /* avoid overwriting the top border line with the ToC header */
  #toc {
    padding-top: 1px;
  }

  /* Avoid page breaks inside dl and author address entries */
  .vcard {
    page-break-inside: avoid;
  }

}
/* Avoid wrapping of URLs in references */
@media screen {
  .references a {
    white-space: nowrap;
  }
}
/* Tweak the bcp14 keyword presentation */
.bcp14 {
  font-variant: small-caps;
  font-weight: bold;
  font-size: 0.9em;
}
/* Tweak the invisible space above H* in order not to overlay links in text above */
 h2 {
  margin-top: -18px;  /* provide offset for in-page anchors */
  padding-top: 31px;
 }
 h3 {
  margin-top: -18px;  /* provide offset for in-page anchors */
  padding-top: 24px;
 }
 h4 {
  margin-top: -18px;  /* provide offset for in-page anchors */
  padding-top: 24px;
 }
/* Float artwork pilcrow to the right */
@media screen {
  .artwork a.pilcrow {
    display: block;
    line-height: 0.7;
    margin-top: 0.15em;
  }
}
/* Make pilcrows on dd visible */
@media screen {
  dd:hover > a.pilcrow {
    visibility: visible;
  }
}
/* Make the placement of figcaption match that of a table's caption
   by removing the figure's added bottom margin */
.alignLeft.art-text,
.alignCenter.art-text,
.alignRight.art-text {
   margin-bottom: 0;
}
.alignLeft,
.alignCenter,
.alignRight {
  margin: 1em 0 0 0;
}
/* In print, the pilcrow won't show on hover, so prevent it from taking up space,
   possibly even requiring a new line */
@media print {
  a.pilcrow {
    display: none;
  }
}
/* Styling for the external metadata */
div#external-metadata {
  background-color: #eee;
  padding: 0.5em;
  margin-bottom: 0.5em;
  display: none;
}
div#internal-metadata {
  padding: 0.5em;                       /* to match the external-metadata padding */
}
/* Styling for title RFC Number */
h1#rfcnum {
  clear: both;
  margin: 0 0 -1em;
  padding: 1em 0 0 0;
}
/* Make .olPercent look the same as <ol><li> */
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<table class="ears">
<thead><tr>
<td class="left">RFC 8746</td>
<td class="center">CBOR tags for typed arrays</td>
<td class="right">February 2020</td>
</tr></thead>
<tfoot><tr>
<td class="left">Bormann</td>
<td class="center">Standards Track</td>
<td class="right">[Page]</td>
</tr></tfoot>
</table>
<div id="external-metadata" class="document-information"></div>
<div id="internal-metadata" class="document-information">
<dl id="identifiers">
<dt class="label-stream">Stream:</dt>
<dd class="stream">Internet Engineering Task Force (IETF)</dd>
<dt class="label-rfc">RFC:</dt>
<dd class="rfc"><a href="https://www.rfc-editor.org/rfc/rfc8746" class="eref">8746</a></dd>
<dt class="label-category">Category:</dt>
<dd class="category">Standards Track</dd>
<dt class="label-published">Published:</dt>
<dd class="published">
<time datetime="2020-02" class="published">February 2020</time>
    </dd>
<dt class="label-issn">ISSN:</dt>
<dd class="issn">2070-1721</dd>
<dt class="label-authors">Author:</dt>
<dd class="authors">
<div class="author">
      <div class="author-name">C. Bormann, <span class="editor">Ed.</span>
</div>
<div class="org">Universität Bremen TZI</div>
</div>
</dd>
</dl>
</div>
<h1 id="rfcnum">RFC 8746</h1>
<h1 id="title">Concise Binary Object Representation (CBOR) Tags for Typed Arrays</h1>
<section id="section-abstract">
      <h2 id="abstract"><a href="#abstract" class="selfRef">Abstract</a></h2>
<p id="section-abstract-1">The Concise Binary Object Representation (CBOR), as defined in RFC
      7049, is a data format whose design goals include the possibility of
      extremely small code size, fairly small message size, and extensibility
      without the need for version negotiation.<a href="#section-abstract-1" class="pilcrow">¶</a></p>
<p id="section-abstract-2">This document makes use of this extensibility to define a number of
      CBOR tags for typed arrays of numeric data, as well as additional
      tags for multi-dimensional and homogeneous arrays.  It is intended as
      the reference document for the IANA registration of the CBOR tags
      defined.<a href="#section-abstract-2" class="pilcrow">¶</a></p>
</section>
<div id="status-of-memo">
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        <h2 id="name-status-of-this-memo">
<a href="#name-status-of-this-memo" class="section-name selfRef">Status of This Memo</a>
        </h2>
<p id="section-boilerplate.1-1">
            This is an Internet Standards Track document.<a href="#section-boilerplate.1-1" class="pilcrow">¶</a></p>
<p id="section-boilerplate.1-2">
            This document is a product of the Internet Engineering Task Force
            (IETF).  It represents the consensus of the IETF community.  It has
            received public review and has been approved for publication by
            the Internet Engineering Steering Group (IESG).  Further
            information on Internet Standards is available in Section 2 of 
            RFC 7841.<a href="#section-boilerplate.1-2" class="pilcrow">¶</a></p>
<p id="section-boilerplate.1-3">
            Information about the current status of this document, any
            errata, and how to provide feedback on it may be obtained at
            <span><a href="https://www.rfc-editor.org/info/rfc8746">https://www.rfc-editor.org/info/rfc8746</a></span>.<a href="#section-boilerplate.1-3" class="pilcrow">¶</a></p>
</section>
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<div id="copyright">
<section id="section-boilerplate.2">
        <h2 id="name-copyright-notice">
<a href="#name-copyright-notice" class="section-name selfRef">Copyright Notice</a>
        </h2>
<p id="section-boilerplate.2-1">
            Copyright (c) 2020 IETF Trust and the persons identified as the
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            This document is subject to BCP 78 and the IETF Trust's Legal
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            publication of this document. Please review these documents
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            document must include Simplified BSD License text as described in
            Section 4.e of the Trust Legal Provisions and are provided without
            warranty as described in the Simplified BSD License.<a href="#section-boilerplate.2-2" class="pilcrow">¶</a></p>
</section>
</div>
<div id="toc">
<section id="section-toc.1">
        <a href="#" onclick="scroll(0,0)" class="toplink">▲</a><h2 id="name-table-of-contents">
<a href="#name-table-of-contents" class="section-name selfRef">Table of Contents</a>
        </h2>
<nav class="toc"><ul class="toc ulEmpty">
<li class="toc ulEmpty" id="section-toc.1-1.1">
            <p id="section-toc.1-1.1.1"><a href="#section-1" class="xref">1</a>.  <a href="#name-introduction" class="xref">Introduction</a><a href="#section-toc.1-1.1.1" class="pilcrow">¶</a></p>
<ul class="toc ulEmpty">
<li class="toc ulEmpty" id="section-toc.1-1.1.2.1">
                <p id="section-toc.1-1.1.2.1.1"><a href="#section-1.1" class="xref">1.1</a>.  <a href="#name-terminology" class="xref">Terminology</a><a href="#section-toc.1-1.1.2.1.1" class="pilcrow">¶</a></p>
</li>
</ul>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.2">
            <p id="section-toc.1-1.2.1"><a href="#section-2" class="xref">2</a>.  <a href="#name-typed-arrays" class="xref">Typed Arrays</a><a href="#section-toc.1-1.2.1" class="pilcrow">¶</a></p>
<ul class="toc ulEmpty">
<li class="toc ulEmpty" id="section-toc.1-1.2.2.1">
                <p id="section-toc.1-1.2.2.1.1"><a href="#section-2.1" class="xref">2.1</a>.  <a href="#name-types-of-numbers" class="xref">Types of Numbers</a><a href="#section-toc.1-1.2.2.1.1" class="pilcrow">¶</a></p>
</li>
</ul>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.3">
            <p id="section-toc.1-1.3.1"><a href="#section-3" class="xref">3</a>.  <a href="#name-additional-array-tags" class="xref">Additional Array Tags</a><a href="#section-toc.1-1.3.1" class="pilcrow">¶</a></p>
<ul class="toc ulEmpty">
<li class="toc ulEmpty" id="section-toc.1-1.3.2.1">
                <p id="section-toc.1-1.3.2.1.1"><a href="#section-3.1" class="xref">3.1</a>.  <a href="#name-multi-dimensional-array" class="xref">Multi-dimensional Array</a><a href="#section-toc.1-1.3.2.1.1" class="pilcrow">¶</a></p>
<ul class="toc ulEmpty">
<li class="toc ulEmpty" id="section-toc.1-1.3.2.1.2.1">
                    <p id="section-toc.1-1.3.2.1.2.1.1"><a href="#section-3.1.1" class="xref">3.1.1</a>.  <a href="#name-row-major-order" class="xref">Row-Major Order</a><a href="#section-toc.1-1.3.2.1.2.1.1" class="pilcrow">¶</a></p>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.3.2.1.2.2">
                    <p id="section-toc.1-1.3.2.1.2.2.1"><a href="#section-3.1.2" class="xref">3.1.2</a>.  <a href="#name-column-major-order" class="xref">Column-Major Order</a><a href="#section-toc.1-1.3.2.1.2.2.1" class="pilcrow">¶</a></p>
</li>
</ul>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.3.2.2">
                <p id="section-toc.1-1.3.2.2.1"><a href="#section-3.2" class="xref">3.2</a>.  <a href="#name-homogeneous-array" class="xref">Homogeneous Array</a><a href="#section-toc.1-1.3.2.2.1" class="pilcrow">¶</a></p>
</li>
</ul>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.4">
            <p id="section-toc.1-1.4.1"><a href="#section-4" class="xref">4</a>.  <a href="#name-discussion" class="xref">Discussion</a><a href="#section-toc.1-1.4.1" class="pilcrow">¶</a></p>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.5">
            <p id="section-toc.1-1.5.1"><a href="#section-5" class="xref">5</a>.  <a href="#name-cddl-typenames" class="xref">CDDL Typenames</a><a href="#section-toc.1-1.5.1" class="pilcrow">¶</a></p>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.6">
            <p id="section-toc.1-1.6.1"><a href="#section-6" class="xref">6</a>.  <a href="#name-iana-considerations" class="xref">IANA Considerations</a><a href="#section-toc.1-1.6.1" class="pilcrow">¶</a></p>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.7">
            <p id="section-toc.1-1.7.1"><a href="#section-7" class="xref">7</a>.  <a href="#name-security-considerations" class="xref">Security Considerations</a><a href="#section-toc.1-1.7.1" class="pilcrow">¶</a></p>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.8">
            <p id="section-toc.1-1.8.1"><a href="#section-8" class="xref">8</a>.  <a href="#name-references" class="xref">References</a><a href="#section-toc.1-1.8.1" class="pilcrow">¶</a></p>
<ul class="toc ulEmpty">
<li class="toc ulEmpty" id="section-toc.1-1.8.2.1">
                <p id="section-toc.1-1.8.2.1.1"><a href="#section-8.1" class="xref">8.1</a>.  <a href="#name-normative-references" class="xref">Normative References</a><a href="#section-toc.1-1.8.2.1.1" class="pilcrow">¶</a></p>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.8.2.2">
                <p id="section-toc.1-1.8.2.2.1"><a href="#section-8.2" class="xref">8.2</a>.  <a href="#name-informative-references" class="xref">Informative References</a><a href="#section-toc.1-1.8.2.2.1" class="pilcrow">¶</a></p>
</li>
</ul>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.9">
            <p id="section-toc.1-1.9.1"><a href="#section-appendix.a" class="xref"></a><a href="#name-acknowledgements" class="xref">Acknowledgements</a><a href="#section-toc.1-1.9.1" class="pilcrow">¶</a></p>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.10">
            <p id="section-toc.1-1.10.1"><a href="#section-appendix.b" class="xref"></a><a href="#name-contributors" class="xref">Contributors</a><a href="#section-toc.1-1.10.1" class="pilcrow">¶</a></p>
</li>
<li class="toc ulEmpty" id="section-toc.1-1.11">
            <p id="section-toc.1-1.11.1"><a href="#section-appendix.c" class="xref"></a><a href="#name-authors-address" class="xref">Author's Address</a><a href="#section-toc.1-1.11.1" class="pilcrow">¶</a></p>
</li>
</ul>
</nav>
</section>
</div>
<div id="intro">
<section id="section-1">
      <h2 id="name-introduction">
<a href="#section-1" class="section-number selfRef">1. </a><a href="#name-introduction" class="section-name selfRef">Introduction</a>
      </h2>
<p id="section-1-1">The Concise Binary Object Representation (CBOR) <span>[<a href="#RFC7049" class="xref">RFC7049</a>]</span> provides for the interchange of
      structured data without a requirement for a pre-agreed schema.  <span>[<a href="#RFC7049" class="xref">RFC7049</a>]</span> defines a basic set of data types as well as a
      tagging mechanism that enables extending the set of data types supported
      via an IANA registry.<a href="#section-1-1" class="pilcrow">¶</a></p>
<p id="section-1-2">Recently, a simple form of typed arrays of numeric data has received
      interest both in the Web graphics community <span>[<a href="#TypedArray" class="xref">TypedArray</a>]</span> and in the JavaScript specification (see <a href="https://www.ecma-international.org/ecma-262/10.0/index.html#sec-typedarray-objects">Section
      22.2</a> of <span>[<a href="#ECMA-ES10" class="xref">ECMA-ES10</a>]</span>) as well as
      in corresponding implementations <span>[<a href="#ArrayBuffer" class="xref">ArrayBuffer</a>]</span>.<a href="#section-1-2" class="pilcrow">¶</a></p>
<p id="section-1-3">Since these typed arrays may carry significant amounts of data, there
      is interest in interchanging them in CBOR without the need of lengthy
      conversion of each number in the array.  This can also save space
      overhead with encoding a type for each element of an array.<a href="#section-1-3" class="pilcrow">¶</a></p>
<p id="section-1-4">This document defines a number of interrelated CBOR tags that cover
      these typed arrays, as well as additional tags for multi-dimensional and
      homogeneous arrays.  It is intended as the reference document for the
      IANA registration of the tags defined.<a href="#section-1-4" class="pilcrow">¶</a></p>
<p id="section-1-5">Note that an application that generates CBOR with these tags has
      considerable freedom in choosing variants (e.g., with respect to
      endianness, embedded type (signed vs. unsigned), and number of bits per
      element) or whether a tag defined in this specification is used at all
      instead of more basic CBOR.  In contrast to representation variants of
      single CBOR numbers, there is no representation that could be identified
      as "preferred".  If deterministic encoding is desired in a CBOR-based
      protocol making use of these tags, the protocol has to define which of
      the encoding variants are used for each individual case.<a href="#section-1-5" class="pilcrow">¶</a></p>
<div id="terms">
<section id="section-1.1">
        <h3 id="name-terminology">
<a href="#section-1.1" class="section-number selfRef">1.1. </a><a href="#name-terminology" class="section-name selfRef">Terminology</a>
        </h3>
<p id="section-1.1-1">
    The key words "<span class="bcp14">MUST</span>", "<span class="bcp14">MUST NOT</span>",
    "<span class="bcp14">REQUIRED</span>", "<span class="bcp14">SHALL</span>", "<span class="bcp14">SHALL NOT</span>", "<span class="bcp14">SHOULD</span>", "<span class="bcp14">SHOULD NOT</span>",
    "<span class="bcp14">RECOMMENDED</span>", "<span class="bcp14">NOT RECOMMENDED</span>",
    "<span class="bcp14">MAY</span>", and "<span class="bcp14">OPTIONAL</span>" in this document are
    to be interpreted as described in BCP 14 <span>[<a href="#RFC2119" class="xref">RFC2119</a>]</span>
          <span>[<a href="#RFC8174" class="xref">RFC8174</a>]</span> when, and only when, they appear in all capitals,
    as shown here.<a href="#section-1.1-1" class="pilcrow">¶</a></p>
<p id="section-1.1-2">The term "byte" is used in its now-customary sense as a synonym for
        "octet".  Where bit arithmetic is explained, this document uses
        familiar notation from the programming language C <span>[<a href="#C" class="xref">C</a>]</span> (including C++14's 0bnnn binary literals <span>[<a href="#CPlusPlus" class="xref">CPlusPlus</a>]</span>) with the exception of the
        operator "**", which stands for exponentiation.<a href="#section-1.1-2" class="pilcrow">¶</a></p>
<p id="section-1.1-3">The term "array" is used in a general sense in this document unless
        further specified.  The term "classical CBOR array" describes an array
        represented with CBOR major type 4.  A "homogeneous array" is an array
        of elements that are all the same type (the term is neutral as to
        whether that is a representation type or an application data model
        type).<a href="#section-1.1-3" class="pilcrow">¶</a></p>
<p id="section-1.1-4">The terms "big endian" and "little endian" are used to indicate a
        most significant byte first (MSB first) representation of integers and
        a least significant byte first (LSB first) representation,
        respectively.<a href="#section-1.1-4" class="pilcrow">¶</a></p>
</section>
</div>
</section>
</div>
<div id="typedarrays">
<section id="section-2">
      <h2 id="name-typed-arrays">
<a href="#section-2" class="section-number selfRef">2. </a><a href="#name-typed-arrays" class="section-name selfRef">Typed Arrays</a>
      </h2>
<p id="section-2-1">Typed arrays are homogeneous arrays of numbers, all of which are
      encoded in a single form of binary representation.  The concatenation of
      these representations is encoded as a single CBOR byte string (major
      type 2), enclosed by a single tag indicating the type and encoding of
      all the numbers represented in the byte string.<a href="#section-2-1" class="pilcrow">¶</a></p>
<div id="dataTypes">
<section id="section-2.1">
        <h3 id="name-types-of-numbers">
<a href="#section-2.1" class="section-number selfRef">2.1. </a><a href="#name-types-of-numbers" class="section-name selfRef">Types of Numbers</a>
        </h3>
<p id="section-2.1-1">Three classes of numbers are of interest: unsigned integers (uint),
        signed integers (two's complement, sint), and IEEE 754 binary floating
        point numbers (which are always signed).  For each of these classes,
        there are multiple representation lengths in active use:<a href="#section-2.1-1" class="pilcrow">¶</a></p>
<span id="name-length-values"></span><div id="lengths">
<table class="center" id="table-1">
          <caption>
<a href="#table-1" class="selfRef">Table 1</a>:
<a href="#name-length-values" class="selfRef">Length Values</a>
          </caption>
<thead>
            <tr>
              <th class="text-left" rowspan="1" colspan="1">Length ll</th>
              <th class="text-left" rowspan="1" colspan="1">uint</th>
              <th class="text-left" rowspan="1" colspan="1">sint</th>
              <th class="text-left" rowspan="1" colspan="1">float</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td class="text-left" rowspan="1" colspan="1">0</td>
              <td class="text-left" rowspan="1" colspan="1">uint8</td>
              <td class="text-left" rowspan="1" colspan="1">sint8</td>
              <td class="text-left" rowspan="1" colspan="1">binary16</td>
            </tr>
            <tr>
              <td class="text-left" rowspan="1" colspan="1">1</td>
              <td class="text-left" rowspan="1" colspan="1">uint16</td>
              <td class="text-left" rowspan="1" colspan="1">sint16</td>
              <td class="text-left" rowspan="1" colspan="1">binary32</td>
            </tr>
            <tr>
              <td class="text-left" rowspan="1" colspan="1">2</td>
              <td class="text-left" rowspan="1" colspan="1">uint32</td>
              <td class="text-left" rowspan="1" colspan="1">sint32</td>
              <td class="text-left" rowspan="1" colspan="1">binary64</td>
            </tr>
            <tr>
              <td class="text-left" rowspan="1" colspan="1">3</td>
              <td class="text-left" rowspan="1" colspan="1">uint64</td>
              <td class="text-left" rowspan="1" colspan="1">sint64</td>
              <td class="text-left" rowspan="1" colspan="1">binary128</td>
            </tr>
          </tbody>
        </table>
</div>
<p id="section-2.1-3">Here, sintN stands for a signed integer of exactly N bits (for
        instance, sint16), and uintN stands for an unsigned integer of exactly
        N bits (for instance, uint32).  The name binaryN stands for the number
        form of the same name defined in IEEE 754 <span>[<a href="#IEEE754" class="xref">IEEE754</a>]</span>.<a href="#section-2.1-3" class="pilcrow">¶</a></p>
<p id="section-2.1-4">Since one objective of these tags is to be able to directly ship the
 ArrayBuffers underlying the Typed Arrays without re-encoding them, and these
 may be either in big-endian (network byte order) or in little-endian form, we
 need to define tags for both variants.<a href="#section-2.1-4" class="pilcrow">¶</a></p>
<p id="section-2.1-5">In total, this leads to 24 variants.  In the tag, we need to
        express the choice between integer and floating point, the signedness
        (for integers), the endianness, and one of the four length values.<a href="#section-2.1-5" class="pilcrow">¶</a></p>
<p id="section-2.1-6">In order to simplify implementation, a range of tags is being
        allocated that allows retrieving all this information from the bits of
        the tag: tag values from 64 to 87.<a href="#section-2.1-6" class="pilcrow">¶</a></p>
<p id="section-2.1-7">The value is split up into 5 bit fields: 0b010, f, s, e, and ll as
        detailed in <a href="#fields" class="xref">Table 2</a>.<a href="#section-2.1-7" class="pilcrow">¶</a></p>
<span id="name-bit-fields-in-the-low-8-bit"></span><div id="fields">
<table class="center" id="table-2">
          <caption>
<a href="#table-2" class="selfRef">Table 2</a>:
<a href="#name-bit-fields-in-the-low-8-bit" class="selfRef">Bit Fields in the Low 8 Bits of the Tag</a>
          </caption>
<thead>
            <tr>
              <th class="text-left" rowspan="1" colspan="1">Field</th>
              <th class="text-left" rowspan="1" colspan="1">Use</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td class="text-left" rowspan="1" colspan="1">0b010</td>
              <td class="text-left" rowspan="1" colspan="1">the constant bits 0, 1, 0</td>
            </tr>
            <tr>
              <td class="text-left" rowspan="1" colspan="1">f</td>
              <td class="text-left" rowspan="1" colspan="1">0 for integer, 1 for float</td>
            </tr>
            <tr>
              <td class="text-left" rowspan="1" colspan="1">s</td>
              <td class="text-left" rowspan="1" colspan="1">0 for float or unsigned integer, 1 for signed integer</td>
            </tr>
            <tr>
              <td class="text-left" rowspan="1" colspan="1">e</td>
              <td class="text-left" rowspan="1" colspan="1">0 for big endian, 1 for little endian</td>
            </tr>
            <tr>
              <td class="text-left" rowspan="1" colspan="1">ll</td>
              <td class="text-left" rowspan="1" colspan="1">A number for the length (<a href="#lengths" class="xref">Table 1</a>).</td>
            </tr>
          </tbody>
        </table>
</div>
<p id="section-2.1-9">The number of bytes in each array element can then be calculated by
        <code>2**(f + ll)</code> (or <code>1 &lt;&lt; (f + ll)</code> in a typical
        programming language).  (Notice that 0f and ll are the two least
        significant bits, respectively, of each 4-bit nibble in the byte.)<a href="#section-2.1-9" class="pilcrow">¶</a></p>
<p id="section-2.1-10">In the CBOR representation, the total number of elements in the
        array is not expressed explicitly but is implied from the length of
        the byte string and the length of each representation.  It can be
        computed from the length, in bytes, of the byte string comprising the
        representation of the array by inverting the previous formula:
        <code>bytelength &gt;&gt; (f + ll)</code>.<a href="#section-2.1-10" class="pilcrow">¶</a></p>
<p id="section-2.1-11">For the uint8/sint8 values, the endianness is redundant.  Only the
        tag for the big-endian variant is used and assigned as such.  The tag
        that would signify the little-endian variant of sint8 <span class="bcp14">MUST NOT</span> be used; its tag number is marked as reserved.  As a
        special case, the tag that would signify the little-endian variant of
        uint8 is instead assigned to signify that the numbers in the array are
        using clamped conversion from integers, as described in more detail in
        <a href="http://www.ecma-international.org/ecma-262/6.0/#sec-touint8clamp">Section 7.1.11</a>
        of the ES10 JavaScript specification (<code>ToUint8Clamp</code>) <span>[<a href="#ECMA-ES10" class="xref">ECMA-ES10</a>]</span>; the assumption here is that a
        program-internal representation of this array after decoding would be
        marked this way for further processing providing "roundtripping" of
        JavaScript-typed arrays through CBOR.<a href="#section-2.1-11" class="pilcrow">¶</a></p>
<p id="section-2.1-12">IEEE 754 binary floating numbers are always signed.  Therefore, for
        the float variants (<code>f</code> == 1), there is no need to distinguish
        between signed and unsigned variants; the <code>s</code> bit is always
        zero.  The tag numbers where <code>s</code> would be one (which would have
        tag values 88 to 95) remain free to use by other specifications.<a href="#section-2.1-12" class="pilcrow">¶</a></p>
</section>
</div>
</section>
</div>
<div id="additional-array-tags">
<section id="section-3">
      <h2 id="name-additional-array-tags">
<a href="#section-3" class="section-number selfRef">3. </a><a href="#name-additional-array-tags" class="section-name selfRef">Additional Array Tags</a>
      </h2>
<p id="section-3-1">This specification defines three additional array tags.  The
      Multi-dimensional Array tags can be combined with classical CBOR arrays
      as well as with Typed Arrays in order to build multi-dimensional arrays
      with constant numbers of elements in the sub-arrays.  The Homogeneous
      Array tag can be used as a signal by an application to identify a
      classical CBOR array as a homogeneous array, even when a Typed Array
      does not apply.<a href="#section-3-1" class="pilcrow">¶</a></p>
<div id="multi-dimensional-array">
<section id="section-3.1">
        <h3 id="name-multi-dimensional-array">
<a href="#section-3.1" class="section-number selfRef">3.1. </a><a href="#name-multi-dimensional-array" class="section-name selfRef">Multi-dimensional Array</a>
        </h3>
<p id="section-3.1-1">A multi-dimensional array is represented as a tagged array that
        contains two (one-dimensional) arrays.  The first array defines the
        dimensions of the multi-dimensional array (in the sequence of outer
        dimensions towards inner dimensions) while the second array represents
        the contents of the multi-dimensional array.  If the second array is
        itself tagged as a Typed Array, then the element type of the
        multi-dimensional array is known to be the same type as that of the
        Typed Array.<a href="#section-3.1-1" class="pilcrow">¶</a></p>
<p id="section-3.1-2">Two tags are defined by this document: one for elements arranged in
        row-major order and another for column-major order <span>[<a href="#RowColMajor" class="xref">RowColMajor</a>]</span>.<a href="#section-3.1-2" class="pilcrow">¶</a></p>
<div id="row-major-order">
<section id="section-3.1.1">
          <h4 id="name-row-major-order">
<a href="#section-3.1.1" class="section-number selfRef">3.1.1. </a><a href="#name-row-major-order" class="section-name selfRef">Row-Major Order</a>
          </h4>
<dl class="dlParallel" id="section-3.1.1-1">
            <dt id="section-3.1.1-1.1">Tag:</dt>
<dd id="section-3.1.1-1.2">
  40<a href="#section-3.1.1-1.2" class="pilcrow">¶</a>
</dd>
<dt id="section-3.1.1-1.3">Data Item:</dt>
<dd id="section-3.1.1-1.4">
  Array (major type 4) of two arrays: one array (major type 4) of dimensions,
  which are unsigned integers distinct from zero; and one array (any one of a
  CBOR array of major type 4, a Typed Array, or a Homogeneous Array) of
  elements.<a href="#section-3.1.1-1.4" class="pilcrow">¶</a>
</dd>
</dl>
<p id="section-3.1.1-2">Data in the second array consists of consecutive values where the
          last dimension is considered contiguous (row-major order).<a href="#section-3.1.1-2" class="pilcrow">¶</a></p>
<p id="section-3.1.1-3"><a href="#ex-multidim" class="xref">Figure 1</a> shows a declaration
          of a two-dimensional array in the C language, a representation of
          that in CBOR using both a multi-dimensional array tag and a typed
          array tag.<a href="#section-3.1.1-3" class="pilcrow">¶</a></p>
<span id="name-multi-dimensional-array-in-"></span><div id="ex-multidim">
<figure id="figure-1">
            <div id="section-3.1.1-4.1">
<pre class="sourcecode lang-C">
uint16_t a[2][3] = {
  {2, 4, 8},   /* row 0 */
  {4, 16, 256},
};

&lt;Tag 40&gt; # multi-dimensional array tag
   82       # array(2)
     82      # array(2)
       02     # unsigned(2) 1st Dimension
       03     # unsigned(3) 2nd Dimension
     &lt;Tag 65&gt; # uint16 array
       4c     # byte string(12)
         0002 # unsigned(2)
         0004 # unsigned(4)
         0008 # unsigned(8)
         0004 # unsigned(4)
         0010 # unsigned(16)
         0100 # unsigned(256)
</pre>
</div>
<figcaption><a href="#figure-1" class="selfRef">Figure 1</a>:
<a href="#name-multi-dimensional-array-in-" class="selfRef">Multi-dimensional Array in C and CBOR</a>
            </figcaption></figure>
</div>
<p id="section-3.1.1-5"><a href="#ex-multidim1" class="xref">Figure 2</a> shows the same
          two-dimensional array using the multi-dimensional array tag in
          conjunction with a basic CBOR array (which, with the small numbers
          chosen for the example, happens to be shorter).<a href="#section-3.1.1-5" class="pilcrow">¶</a></p>
<span id="name-multi-dimensional-array-usi"></span><div id="ex-multidim1">
<figure id="figure-2">
            <div id="section-3.1.1-6.1">
<pre class="sourcecode lang-CBOR">
&lt;Tag 40&gt; # multi-dimensional array tag
   82       # array(2)
     82      # array(2)
       02     # unsigned(2) 1st Dimension
       03     # unsigned(3) 2nd Dimension
     86     # array(6)
       02      # unsigned(2)
       04      # unsigned(4)
       08      # unsigned(8)
       04      # unsigned(4)
       10      # unsigned(16)
       19 0100 # unsigned(256)
</pre>
</div>
<figcaption><a href="#figure-2" class="selfRef">Figure 2</a>:
<a href="#name-multi-dimensional-array-usi" class="selfRef">Multi-dimensional Array Using Basic CBOR Array</a>
            </figcaption></figure>
</div>
</section>
</div>
<div id="column-major-order">
<section id="section-3.1.2">
          <h4 id="name-column-major-order">
<a href="#section-3.1.2" class="section-number selfRef">3.1.2. </a><a href="#name-column-major-order" class="section-name selfRef">Column-Major Order</a>
          </h4>
<p id="section-3.1.2-1">The multi-dimensional arrays specified in the previous
          sub-subsection are in "row major" order, which is the preferred
          order for the purposes of this specification.  An analogous
          representation that uses "column major" order arrays is provided in
          this subsection under the tag 1040, as illustrated in <a href="#ex-multidim2" class="xref">Figure 3</a>.<a href="#section-3.1.2-1" class="pilcrow">¶</a></p>
<dl class="dlParallel" id="section-3.1.2-2">
            <dt id="section-3.1.2-2.1">Tag:</dt>
<dd id="section-3.1.2-2.2">
  1040<a href="#section-3.1.2-2.2" class="pilcrow">¶</a>
</dd>
<dt id="section-3.1.2-2.3">Data Item:</dt>
<dd id="section-3.1.2-2.4">
  The same as tag 40, except the data in the second array consists of
  consecutive values where the first dimension is considered contiguous
  (column-major order).<a href="#section-3.1.2-2.4" class="pilcrow">¶</a>
</dd>
</dl>
<span id="name-multi-dimensional-array-usin"></span><div id="ex-multidim2">
<figure id="figure-3">
            <div id="section-3.1.2-3.1">
<pre class="sourcecode lang-CBOR">
&lt;Tag 1040&gt; # multi-dimensional array tag, column-major order
   82       # array(2)
     82      # array(2)
       02     # unsigned(2) 1st Dimension
       03     # unsigned(3) 2nd Dimension
     86     # array(6)
       02      # unsigned(2)
       04      # unsigned(4)
       04      # unsigned(4)
       10      # unsigned(16)
       08      # unsigned(8)
       19 0100 # unsigned(256)
</pre>
</div>
<figcaption><a href="#figure-3" class="selfRef">Figure 3</a>:
<a href="#name-multi-dimensional-array-usin" class="selfRef">Multi-dimensional Array Using Basic CBOR Array, Column-Major Order</a>
            </figcaption></figure>
</div>
</section>
</div>
</section>
</div>
<div id="homogeneous-array">
<section id="section-3.2">
        <h3 id="name-homogeneous-array">
<a href="#section-3.2" class="section-number selfRef">3.2. </a><a href="#name-homogeneous-array" class="section-name selfRef">Homogeneous Array</a>
        </h3>
<dl class="dlParallel" id="section-3.2-1">
          <dt id="section-3.2-1.1">Tag:</dt>
<dd id="section-3.2-1.2">
  41<a href="#section-3.2-1.2" class="pilcrow">¶</a>
</dd>
<dt id="section-3.2-1.3">Data Item:</dt>
<dd id="section-3.2-1.4">
  Array (major type 4)<a href="#section-3.2-1.4" class="pilcrow">¶</a>
</dd>
</dl>
<p id="section-3.2-2">This tag identifies the classical CBOR array (a one-dimensional
        array) tagged by it as a homogeneous array, that is, it has elements
        that are all of the same application model data type.  The element
        type of the array is therefore determined by the application model
        data type of the first array element.<a href="#section-3.2-2" class="pilcrow">¶</a></p>
<p id="section-3.2-3">This can be used in application data models that apply specific
        semantics to homogeneous arrays.  Also, in certain cases,
        implementations in strongly typed languages may be able to create
        native homogeneous arrays of specific types instead of ordered lists
        while decoding.  Which CBOR data items constitute elements of the same
        application type is specific to the application.<a href="#section-3.2-3" class="pilcrow">¶</a></p>
<p id="section-3.2-4"><a href="#ex-homogeneous" class="xref">Figure 4</a> shows an example
        for a homogeneous array of booleans in C++ <span>[<a href="#CPlusPlus" class="xref">CPlusPlus</a>]</span> and CBOR.<a href="#section-3.2-4" class="pilcrow">¶</a></p>
<span id="name-homogeneous-array-in-c-and-"></span><div id="ex-homogeneous">
<figure id="figure-4">
          <div id="section-3.2-5.1">
<pre class="sourcecode lang-C++">
bool boolArray[2] = { true, false };

&lt;Tag 41&gt;  # Homogeneous Array Tag
   82           #array(2)
      F5        # true
      F4        # false
</pre>
</div>
<figcaption><a href="#figure-4" class="selfRef">Figure 4</a>:
<a href="#name-homogeneous-array-in-c-and-" class="selfRef">Homogeneous Array in C++ and CBOR</a>
          </figcaption></figure>
</div>
<p id="section-3.2-6"><a href="#ex-homogeneous1" class="xref">Figure 5</a> extends the
        example with a more complex structure.<a href="#section-3.2-6" class="pilcrow">¶</a></p>
<span id="name-homogeneous-array-in-c-and-c"></span><div id="ex-homogeneous1">
<figure id="figure-5">
          <div id="section-3.2-7.1">
<pre class="sourcecode lang-C++">
typedef struct {
  bool active;
  int value;
} foo;
foo myArray[2] = { {true, 3}, {true, -4} };

&lt;Tag 41&gt;
    82  # array(2)
       82  #  array(2)
             F5  # true
             03  # 3
       82 # array(2)
             F5  # true
             23  # -4
</pre>
</div>
<figcaption><a href="#figure-5" class="selfRef">Figure 5</a>:
<a href="#name-homogeneous-array-in-c-and-c" class="selfRef">Homogeneous Array in C++ and CBOR</a>
          </figcaption></figure>
</div>
</section>
</div>
</section>
</div>
<div id="discussion">
<section id="section-4">
      <h2 id="name-discussion">
<a href="#section-4" class="section-number selfRef">4. </a><a href="#name-discussion" class="section-name selfRef">Discussion</a>
      </h2>
<p id="section-4-1">Support for both little- and big-endian representation may seem out
      of character with CBOR, which is otherwise fully big endian.  This
      support is in line with the intended use of the typed arrays and the
      objective not to require conversion of each array element.<a href="#section-4-1" class="pilcrow">¶</a></p>
<p id="section-4-2">This specification allocates a sizable chunk out of the single-byte
      tag space.  This use of code point space is justified by the wide use of
      typed arrays in data interchange.<a href="#section-4-2" class="pilcrow">¶</a></p>
<p id="section-4-3">Providing a column-major order variant of the multi-dimensional array
      may seem superfluous to some and useful to others.  It is cheap to
      define the additional tag so that it is available when actually needed.
      Allocating it out of a different number space makes the preference for
      row-major evident.<a href="#section-4-3" class="pilcrow">¶</a></p>
<p id="section-4-4">Applying a Homogeneous Array tag to a Typed Array would usually be
      redundant and is therefore not provided by the present
      specification.<a href="#section-4-4" class="pilcrow">¶</a></p>
<p id="section-4-5"><a href="#section-4-5" class="pilcrow">¶</a></p>
</section>
</div>
<div id="cddl-typenames">
<section id="section-5">
      <h2 id="name-cddl-typenames">
<a href="#section-5" class="section-number selfRef">5. </a><a href="#name-cddl-typenames" class="section-name selfRef">CDDL Typenames</a>
      </h2>
<p id="section-5-1">For use with CDDL <span>[<a href="#RFC8610" class="xref">RFC8610</a>]</span>, the
      typenames defined in <a href="#tag-cddl" class="xref">Figure 6</a> are
      recommended:<a href="#section-5-1" class="pilcrow">¶</a></p>
<span id="name-recommended-typenames-for-c"></span><div id="tag-cddl">
<figure id="figure-6">
        <div id="section-5-2.1">
<pre class="sourcecode lang-CDDL">
ta-uint8 = #6.64(bstr)
ta-uint16be = #6.65(bstr)
ta-uint32be = #6.66(bstr)
ta-uint64be = #6.67(bstr)
ta-uint8-clamped = #6.68(bstr)
ta-uint16le = #6.69(bstr)
ta-uint32le = #6.70(bstr)
ta-uint64le = #6.71(bstr)
ta-sint8 = #6.72(bstr)
ta-sint16be = #6.73(bstr)
ta-sint32be = #6.74(bstr)
ta-sint64be = #6.75(bstr)
; reserved: #6.76(bstr)
ta-sint16le = #6.77(bstr)
ta-sint32le = #6.78(bstr)
ta-sint64le = #6.79(bstr)
ta-float16be = #6.80(bstr)
ta-float32be = #6.81(bstr)
ta-float64be = #6.82(bstr)
ta-float128be = #6.83(bstr)
ta-float16le = #6.84(bstr)
ta-float32le = #6.85(bstr)
ta-float64le = #6.86(bstr)
ta-float128le = #6.87(bstr)
homogeneous&lt;array&gt; = #6.41(array)
multi-dim&lt;dim, array&gt; = #6.40([dim, array])
multi-dim-column-major&lt;dim, array&gt; = #6.1040([dim, array])
</pre>
</div>
<figcaption><a href="#figure-6" class="selfRef">Figure 6</a>:
<a href="#name-recommended-typenames-for-c" class="selfRef">Recommended Typenames for CDDL</a>
        </figcaption></figure>
</div>
<p id="section-5-3"><a href="#section-5-3" class="pilcrow">¶</a></p>
</section>
</div>
<div id="iana-considerations">
<section id="section-6">
      <h2 id="name-iana-considerations">
<a href="#section-6" class="section-number selfRef">6. </a><a href="#name-iana-considerations" class="section-name selfRef">IANA Considerations</a>
      </h2>
<p id="section-6-1">IANA has allocated the tags in <a href="#tab-tag-values" class="xref">Table 3</a> using this document as the specification reference.
      (The reserved value is for a future revision of typed array tags.)<a href="#section-6-1" class="pilcrow">¶</a></p>
<p id="section-6-2">The allocations were assigned from the "specification required" space
      (24..255) with the exception of 1040, which was assigned from the "first come
      first served" space (256..).<a href="#section-6-2" class="pilcrow">¶</a></p>
<span id="name-values-for-tags"></span><div id="tab-tag-values">
<table class="center" id="table-3">
        <caption>
<a href="#table-3" class="selfRef">Table 3</a>:
<a href="#name-values-for-tags" class="selfRef">Values for Tags</a>
        </caption>
<thead>
          <tr>
            <th class="text-right" rowspan="1" colspan="1">Tag</th>
            <th class="text-left" rowspan="1" colspan="1">Data Item</th>
            <th class="text-left" rowspan="1" colspan="1">Semantics</th>
          </tr>
        </thead>
        <tbody>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">40</td>
            <td class="text-left" rowspan="1" colspan="1">array of two arrays*</td>
            <td class="text-left" rowspan="1" colspan="1">Multi-dimensional Array, row-major order</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">41</td>
            <td class="text-left" rowspan="1" colspan="1">array</td>
            <td class="text-left" rowspan="1" colspan="1">Homogeneous Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">64</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">uint8 Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">65</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">uint16, big endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">66</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">uint32, big endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">67</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">uint64, big endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">68</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">uint8 Typed Array, clamped arithmetic</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">69</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">uint16, little endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">70</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">uint32, little endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">71</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">uint64, little endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">72</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">sint8 Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">73</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">sint16, big endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">74</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">sint32, big endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">75</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">sint64, big endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">76</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">(reserved)</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">77</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">sint16, little endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">78</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">sint32, little endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">79</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">sint64, little endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">80</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">IEEE 754 binary16, big endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">81</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">IEEE 754 binary32, big endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">82</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">IEEE 754 binary64, big endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">83</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">IEEE 754 binary128, big endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">84</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">IEEE 754 binary16, little endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">85</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">IEEE 754 binary32, little endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">86</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">IEEE 754 binary64, little endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">87</td>
            <td class="text-left" rowspan="1" colspan="1">byte string</td>
            <td class="text-left" rowspan="1" colspan="1">IEEE 754 binary128, little endian, Typed Array</td>
          </tr>
          <tr>
            <td class="text-right" rowspan="1" colspan="1">1040</td>
            <td class="text-left" rowspan="1" colspan="1">array of two arrays*</td>
            <td class="text-left" rowspan="1" colspan="1">Multi-dimensional Array, column-major order</td>
          </tr>
        </tbody>
      </table>
</div>
<p id="section-6-4">*40 or 1040 data item: The second element of the outer array in the data
item is a native CBOR array (major type 4) or Typed Array (one of tag
64..87)<a href="#section-6-4" class="pilcrow">¶</a></p>
</section>
</div>
<div id="security-considerations">
<section id="section-7">
      <h2 id="name-security-considerations">
<a href="#section-7" class="section-number selfRef">7. </a><a href="#name-security-considerations" class="section-name selfRef">Security Considerations</a>
      </h2>
<p id="section-7-1">The security considerations of <span>[<a href="#RFC7049" class="xref">RFC7049</a>]</span> apply;
      special attention is drawn to the second paragraph of <span><a href="https://www.rfc-editor.org/rfc/rfc7049#section-8" class="relref">Section 8</a> of [<a href="#RFC7049" class="xref">RFC7049</a>]</span>.<a href="#section-7-1" class="pilcrow">¶</a></p>
<p id="section-7-2">The tag for homogeneous arrays makes a promise about its tagged data
      item, which a maliciously constructed CBOR input can then choose to
      ignore.  As always, the decoder therefore has to ensure that it is not
      driven into an undefined state by array elements that do not fulfill the
      promise, and that it does continue to fulfill its API contract in this
      case as well.<a href="#section-7-2" class="pilcrow">¶</a></p>
<p id="section-7-3">As with all formats that are used for data interchange, an attacker
      may have control over the shape of the data delivered as input to the
      application, which therefore needs to validate that shape before it
      makes it the basis of its further processing.  One unique aspect that
      typed arrays add to this is that an attacker might substitute a
      Uint8ClampedArray for where the application expects a Uint8Array, or
      vice versa, potentially leading to very different (and unexpected)
      processing semantics of the in-memory data structures constructed.
      Applications that could be affected by this will therefore need to be
      careful about making this distinction in their input validation.<a href="#section-7-3" class="pilcrow">¶</a></p>
<p id="section-7-4"><a href="#section-7-4" class="pilcrow">¶</a></p>
</section>
</div>
<section id="section-8">
      <h2 id="name-references">
<a href="#section-8" class="section-number selfRef">8. </a><a href="#name-references" class="section-name selfRef">References</a>
      </h2>
<section id="section-8.1">
        <h3 id="name-normative-references">
<a href="#section-8.1" class="section-number selfRef">8.1. </a><a href="#name-normative-references" class="section-name selfRef">Normative References</a>
        </h3>
<dl class="references">
<dt id="C">[C]</dt>
<dd>
<span class="refAuthor">International Organization for Standardization</span>, <span class="refTitle">"Information technology - Programming languages - C"</span>, <span class="seriesInfo">ISO/IEC 9899:2018, Fourth Edition</span>, <time datetime="2018-06">June 2018</time>. </dd>
<dt id="CPlusPlus">[CPlusPlus]</dt>
<dd>
<span class="refAuthor">International Organization for Standardization</span>, <span class="refTitle">"Programming languages - C++"</span>, <span class="seriesInfo">ISO/IEC 14882:2017, Fifth Edition</span>, <time datetime="2017-12">December 2017</time>. </dd>
<dt id="ECMA-ES10">[ECMA-ES10]</dt>
<dd>
<span class="refAuthor">ECMA International</span>, <span class="refTitle">"ECMAScript 2019 Language Specification"</span>, <span class="refContent">Standard ECMA-262 10th Edition</span>, <time datetime="2019-06">June 2019</time>, <span>&lt;<a href="https://www.ecma-international.org/ecma-262/10.0/index.html">https://www.ecma-international.org/ecma-262/10.0/index.html</a>&gt;</span>. </dd>
<dt id="IEEE754">[IEEE754]</dt>
<dd>
<span class="refAuthor">IEEE</span>, <span class="refTitle">"IEEE Standard for Floating-Point Arithmetic"</span>, <span class="seriesInfo">IEEE 754-2019</span>, <span class="seriesInfo">DOI 10.1109/IEEESTD.2019.8766229</span>, <time></time>, <span>&lt;<a href="https://ieeexplore.ieee.org/document/8766229">https://ieeexplore.ieee.org/document/8766229</a>&gt;</span>. </dd>
<dt id="RFC2119">[RFC2119]</dt>
<dd>
<span class="refAuthor">Bradner, S.</span>, <span class="refTitle">"Key words for use in RFCs to Indicate Requirement Levels"</span>, <span class="seriesInfo">BCP 14</span>, <span class="seriesInfo">RFC 2119</span>, <span class="seriesInfo">DOI 10.17487/RFC2119</span>, <time datetime="1997-03">March 1997</time>, <span>&lt;<a href="https://www.rfc-editor.org/info/rfc2119">https://www.rfc-editor.org/info/rfc2119</a>&gt;</span>. </dd>
<dt id="RFC7049">[RFC7049]</dt>
<dd>
<span class="refAuthor">Bormann, C.</span><span class="refAuthor"> and P. Hoffman</span>, <span class="refTitle">"Concise Binary Object Representation (CBOR)"</span>, <span class="seriesInfo">RFC 7049</span>, <span class="seriesInfo">DOI 10.17487/RFC7049</span>, <time datetime="2013-10">October 2013</time>, <span>&lt;<a href="https://www.rfc-editor.org/info/rfc7049">https://www.rfc-editor.org/info/rfc7049</a>&gt;</span>. </dd>
<dt id="RFC8174">[RFC8174]</dt>
<dd>
<span class="refAuthor">Leiba, B.</span>, <span class="refTitle">"Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words"</span>, <span class="seriesInfo">BCP 14</span>, <span class="seriesInfo">RFC 8174</span>, <span class="seriesInfo">DOI 10.17487/RFC8174</span>, <time datetime="2017-05">May 2017</time>, <span>&lt;<a href="https://www.rfc-editor.org/info/rfc8174">https://www.rfc-editor.org/info/rfc8174</a>&gt;</span>. </dd>
<dt id="RFC8610">[RFC8610]</dt>
<dd>
<span class="refAuthor">Birkholz, H.</span><span class="refAuthor">, Vigano, C.</span><span class="refAuthor">, and C. Bormann</span>, <span class="refTitle">"Concise Data Definition Language (CDDL): A Notational Convention to Express Concise Binary Object Representation (CBOR) and JSON Data Structures"</span>, <span class="seriesInfo">RFC 8610</span>, <span class="seriesInfo">DOI 10.17487/RFC8610</span>, <time datetime="2019-06">June 2019</time>, <span>&lt;<a href="https://www.rfc-editor.org/info/rfc8610">https://www.rfc-editor.org/info/rfc8610</a>&gt;</span>. </dd>
</dl>
</section>
<section id="section-8.2">
        <h3 id="name-informative-references">
<a href="#section-8.2" class="section-number selfRef">8.2. </a><a href="#name-informative-references" class="section-name selfRef">Informative References</a>
        </h3>
<dl class="references">
<dt id="ArrayBuffer">[ArrayBuffer]</dt>
<dd>
<span class="refAuthor">Mozilla Developer Network</span>, <span class="refTitle">"JavaScript typed arrays"</span>, <time datetime="2010-06">June 2010</time>, <span>&lt;<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Typed_arrays">https://developer.mozilla.org/en-US/docs/Web/JavaScript/Typed_arrays</a>&gt;</span>. </dd>
<dt id="RowColMajor">[RowColMajor]</dt>
<dd>
<span class="refAuthor">Wikipedia</span>, <span class="refTitle">"Row- and column-major order"</span>, <time datetime="2019-09">September 2019</time>, <span>&lt;<a href="https://en.wikipedia.org/w/index.php?title=Row-_and_column-major_order&amp;oldid=917905325">https://en.wikipedia.org/w/index.php?title=Row-_and_column-major_order&amp;oldid=917905325</a>&gt;</span>. </dd>
<dt id="TypedArray">[TypedArray]</dt>
<dd>
<span class="refAuthor">Vukicevic, V.</span><span class="refAuthor"> and K. Russell</span>, <span class="refTitle">"Typed Array Specification"</span>, <time datetime="2011-02">February 2011</time>, <span>&lt;<a href="https://web.archive.org/web/20110207024413/http://www.khronos.org/registry/typedarray/specs/latest/">https://web.archive.org/web/20110207024413/http://www.khronos.org/registry/typedarray/specs/latest/</a>&gt;</span>. </dd>
</dl>
</section>
</section>
<div id="acknowledgements">
<section id="section-appendix.a">
      <h2 id="name-acknowledgements">
<a href="#name-acknowledgements" class="section-name selfRef">Acknowledgements</a>
      </h2>
<p id="section-appendix.a-1"><span class="contact-name">Jim Schaad</span> provided helpful comments and reminded us that
      column-major order still is in use.  <span class="contact-name">Jeffrey Yaskin</span> helped improve the
      definition of homogeneous arrays.  IANA helped correct an error in a
      previous draft version.  <span class="contact-name">Francesca Palombini</span> acted as Shepherd, and
      <span class="contact-name">Alexey Melnikov</span> as responsible Area Director.
      <span class="contact-name">Elwyn Davies</span> as Gen-ART
      reviewer and IESG members <span class="contact-name">Martin Vigoureux</span>,
      <span class="contact-name">Adam Roach</span>, <span class="contact-name">Roman       Danyliw</span>,
      and <span class="contact-name">Benjamin Kaduk</span> helped in finding further improvements to the text;
      thanks also to the other reviewers.<a href="#section-appendix.a-1" class="pilcrow">¶</a></p>
</section>
</div>
<div id="contributors">
<section id="section-appendix.b">
      <h2 id="name-contributors">
<a href="#name-contributors" class="section-name selfRef">Contributors</a>
      </h2>
<p id="section-appendix.b-1">The initial draft version of this
      specification was written by <span class="contact-name">Johnathan Roatch</span> &lt;roatch@gmail.com&gt;.
      Many thanks for getting this ball rolling.<a href="#section-appendix.b-1" class="pilcrow">¶</a></p>
<p id="section-appendix.b-2"><span class="contact-name">Glenn Engel</span> suggested the tags for multi-dimensional arrays and
      homogeneous arrays.<a href="#section-appendix.b-2" class="pilcrow">¶</a></p>
</section>
</div>
<div id="authors-addresses">
<section id="section-appendix.c">
      <h2 id="name-authors-address">
<a href="#name-authors-address" class="section-name selfRef">Author's Address</a>
      </h2>
<address class="vcard">
        <div dir="auto" class="left"><span class="fn nameRole">Carsten Bormann (<span class="role">editor</span>)</span></div>
<div dir="auto" class="left"><span class="org">Universität Bremen TZI</span></div>
<div dir="auto" class="left"><span class="street-address">Postfach 330440</span></div>
<div dir="auto" class="left">
<span class="postal-code">D-28359</span> <span class="locality">Bremen</span>
</div>
<div dir="auto" class="left"><span class="country-name">Germany</span></div>
<div class="tel">
<span>Phone:</span>
<a href="tel:+49-421-218-63921" class="tel">+49-421-218-63921</a>
</div>
<div class="email">
<span>Email:</span>
<a href="mailto:cabo@tzi.org" class="email">cabo@tzi.org</a>
</div>
</address>
</section>
</div>
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