\documentclass{article}
\usepackage[LGR,T1]{fontenc}
\usepackage{lmodern}

\usepackage[unicode,colorlinks=true,linkcolor=blue]{hyperref}
% \usepackage{bookmark}

\usepackage[greek,english]{babel}
\usepackage[normalize-symbols]{alphabeta}
\usepackage[utf8]{inputenc}

% \pagestyle{headings}

\begin{document}

\title{Greek and hyperref}
\author{Günter Milde}
\date{2020/10/30}
\maketitle

\noindent
On 2010-11-05, Heiko Oberdiek wrote in comp.text.tex:
%
\begin{quote}
   \textbackslash pdfstringdef (converting TeX code to PDF strings for
   bookmarks) supports NFSS2 and needs active characters. Encoding
   stuff based on the internal font machinery of TeX (letters with
   catcode 11 or 12, ligatures) does not work, because the strings
   don't reach TeX's stomach.
\end{quote}
%
The \emph{greek-fontenc} package allows input of Greek characters in a way
that ``reaches TeX's stomach'' and hence works in both, the main document as
well as in PDF strings (e.g. bookmarks). Hyperref's ``puenc.def`` font
encoding file defines LICR macros for monotonic Greek (Greek characters of
the ``Greek and Coptic'' unicode block).

All utf8-encoded literal Unicode characters work in PDF strings. With
\emph{greek-fontenc} and \emph{greek-inputenc}, this enables use of all
Greek character in text and PDF strings.

\section{Transcription: \ensuregreek{logos}, \foreignlanguage{greek}{logos}}

\textbackslash{}textgreek + LGR transcription or
Greek language (babel) + LGR transcription:
In the PDF-bookmark are Latin letters instead of Greek ones.


\section{Macros:
	    \textlambda\textomicron\textgamma\textomicron\textvarsigma{},
            \lambda\omicron\gamma\omicron\varsigma{},
	    λογος}

\emph{textalpha} package with \textbackslash{}textalpha \ldots
\textbackslash{}textomega macros or \emph{alphabeta} package with
\textbackslash{}alpha \ldots \textbackslash{}Omega macros. With 8-bit TeX
engines (pdflatex), literal Greek Unicode characters are converted to LICR
Macros, too.

Works, if the \texttt{unicode} or \texttt{pdfencoding=auto} option is given
to \emph{hyperref}.%
\footnote{With the ``xpdf'' viewer, Greek letters are not shown
	  in PDF bookmarks.}

The generic short macros from the \emph{alphabeta} package result in
hyperref warnings. See \href{alphabeta-doc.pdf}{alphabeta-doc.pdf} and 
\href{alphabeta-doc.tex}{alphabeta-doc.tex}
for details and workarounds.


\section{LGR + Macros: \foreignlanguage{greek}{
  \textlambda\textomicron\textgamma\textomicron\textvarsigma{}}}

LICR-macro input works also if the font encoding is LGR.

\section{%
  Kerning: \textAlpha\textUpsilon\textLambda{}
  	   \ensuregreek{\textAlpha\textUpsilon\textLambda}
  	   \foreignlanguage{greek}{\textAlpha\textUpsilon\textLambda}%
}

Kerning is impossible if the font encoding is switched for every single
character. To fix this, wrap the Greek part in a command switching to a font
encoding supporting Greek, either \verb+\ensuregreek{...}+ (with package
\emph{textalpha} or \emph{Babel}) or \verb+\foreignlanguage{greek}{...}+
(with \emph{Babel}).

\section{Literal Unicode input}
The following subsection headings contain all characters from the ``Greek
and Coptic'' and ``Greek Extended'' Unicode Blocks that are supported by the
LGR font encoding.
\subsection{ʹ͵ͺ; ΄ ΅ Ά·ΈΉΊΌΎΏΐΑΒΓΔΕΖΗΘΙΚΛΜΝ}
\subsection{ΞΟΠΡΣΤΥΦΧΨΩΪΫϘϚϜϠ}
Greek and Coptic Unicode block: punctuation and uppercase letters

\subsection{άέήίΰαβγδεζηθικλμν}
\subsection{ξοπρςστυφχψωϊϋόύώϐϑϕϖϘϙϛϝϟϡ}

Greek and Coptic Unicode block: lowercase letters

\subsection{ἀἁἂἃἄἅἆἇἈἉἊἋἌἍἎἏ}
\subsection{ἐἑἒἓἔἕἘἙἚἛἜἝ}
\subsection{ἠἡἢἣἤἥἦἧἨἩἪἫἬἭἮἯ}
\subsection{ἰἱἲἳἴἵἶἷἸἹἺἻἼἽἾἿ}
\subsection{ὀὁὂὃὄὅὈὉὊὋὌὍ}
\subsection{ὐὑὒὓὔὕὖὗὙὛὝὟ}
\subsection{ὠὡὢὣὤὥὦὧὨὩὪὫὬὭὮὯ}
\subsection{ὰάὲέὴήὶίὸόὺύὼώ}
\subsection{ᾀᾁᾂᾃᾄᾅᾆᾇᾈᾉᾊᾋᾌᾍᾎᾏ}
\subsection{ᾐᾑᾒᾓᾔᾕᾖᾗᾘᾙᾚᾛᾜᾝᾞᾟ}
\subsection{ᾠᾡᾢᾣᾤᾥᾦᾧᾨᾩᾪᾫᾬᾭᾮᾯ}
\subsection{ᾰᾱᾲᾳᾴᾶᾷᾸᾹᾺΆᾼ᾽ι᾿}
\subsection{῀῁ῂῃῄῆῇῈΈῊΉῌ῍῎῏}
\subsection{ῐῑῒΐῖῗῘῙῚΊ῝῞῟}
\subsection{ῠῡῢΰῤῥῦῧῨῩῪΎῬ῭΅`}
\subsection{ῲῳῴῶῷῸΌῺΏῼ´῾}

Greek Extended Unicode block: Input as literal precomposed Unicode character
works fine.

\section{LICR command input}

\subsection{\ensuregreek{
  \textnumeralsigngreek
  \textnumeralsignlowergreek
  { }\ypogegrammeni
  \texterotimatiko
  \acctonos{ }
  \"'{ }
  \'\textAlpha
  \textanoteleia
  \'\textEpsilon
  \'\textEta
  \'\textIota
  \'\textOmicron
  \'\textUpsilon
  \'\textOmega
  \'"\textiota
  \textAlpha
  \textBeta
  \textGamma
  \textDelta
  \textEpsilon
  \textZeta
  \textEta
  \textTheta
  \textIota
  \textKappa
  \textLambda
  \textMu
  \textNu}}
\subsection{\ensuregreek{
  \textXi
  \textOmicron
  \textPi
  \textRho
  \textSigma
  \textTau
  \textUpsilon
  \textPhi
  \textChi
  \textPsi
  \textOmega
  \"\textIota
  \"\textUpsilon
}}

\subsection{\ensuregreek{
  \'\textalpha
  \'\textepsilon
  \'\texteta
  \'\textiota
  \"'\textupsilon
  \textalpha
  \textbeta
  \textgamma
  \textdelta
  \textepsilon
  \textzeta
  \texteta
  \texttheta
  \textiota
  \textkappa
  \textlambda
  \textmu
  \textnu}}
\subsection{\ensuregreek{
  \textxi
  \textomicron
  \textpi
  \textrho
  \textvarsigma
  \textsigma
  \texttau
  \textupsilon
  \textphi
  \textchi
  \textpsi
  \textomega
  \"\textiota
  \"\textupsilon
  \'\textomicron
  \'\textupsilon
  \'\textomega
  \textbetasymbol
  \textthetasymbol
  \textphisymbol
  \textpisymbol
  \textQoppa
  \textqoppa
  \textStigma
  \textstigma
  \textDigamma
  \textdigamma
  \textKoppa
  \textkoppa
  \textSampi
  \textsampi
}}


Currently, there is no hyperref support for LICR input with non-standard
accents or combined diacritics characters.

\subsection{\ensuregreek{
  \accpsili\textalpha
  \accdasia\textalpha
  \accpsili`\textalpha
  \accdasia`\textalpha
  \accpsili'\textalpha
  \accdasia'\textalpha
  \~>\textalpha
  \~<\textalpha
  \accpsili\textAlpha
  \accdasia\textAlpha
  \accpsili`\textAlpha
  \accdasia`\textAlpha
  \accpsili'\textAlpha
  \accdasia'\textAlpha
  \~>\textAlpha
  \~<\textAlpha
}}
\subsection{\ensuregreek{
  \accpsili\textepsilon
  \accdasia\textepsilon
  \accpsili`\textepsilon
  \accdasia`\textepsilon
  \accpsili'\textepsilon
  \accdasia'\textepsilon
  \accpsili\textEpsilon
  \accdasia\textEpsilon
  \accpsili`\textEpsilon
  \accdasia`\textEpsilon
  \accpsili'\textEpsilon
  \accdasia'\textEpsilon
}}
\subsection{\ensuregreek{
  \accpsili\texteta
  \accdasia\texteta
  \accpsili`\texteta
  \accdasia`\texteta
  \accpsili'\texteta
  \accdasia'\texteta
  \~>\texteta
  \~<\texteta
  \accpsili\textEta
  \accdasia\textEta
  \accpsili`\textEta
  \accdasia`\textEta
  \accpsili'\textEta
  \accdasia'\textEta
  \~>\textEta
  \~<\textEta
}}
\subsection{\ensuregreek{
  \accpsili\textiota
  \accdasia\textiota
  \accpsili`\textiota
  \accdasia`\textiota
  \accpsili'\textiota
  \accdasia'\textiota
  \~>\textiota
  \~<\textiota
  \accpsili\textIota
  \accdasia\textIota
  \accpsili`\textIota
  \accdasia`\textIota
  \accpsili'\textIota
  \accdasia'\textIota
  \~>\textIota
  \~<\textIota
}}
\subsection{\ensuregreek{
  \accpsili\textomicron
  \accdasia\textomicron
  \accpsili`\textomicron
  \accdasia`\textomicron
  \accpsili'\textomicron
  \accdasia'\textomicron
  \accpsili\textOmicron
  \accdasia\textOmicron
  \accpsili`\textOmicron
  \accdasia`\textOmicron
  \accpsili'\textOmicron
  \accdasia'\textOmicron
}}
\subsection{\ensuregreek{
  \accpsili\textupsilon
  \accdasia\textupsilon
  \accpsili`\textupsilon
  \accdasia`\textupsilon
  \accpsili'\textupsilon
  \accdasia'\textupsilon
  \~>\textupsilon
  \~<\textupsilon
  \accdasia\textUpsilon
  \accdasia`\textUpsilon
  \accdasia'\textUpsilon
  \~<\textUpsilon
}}
\subsection{\ensuregreek{
  \accpsili\textomega
  \accdasia\textomega
  \accpsili`\textomega
  \accdasia`\textomega
  \accpsili'\textomega
  \accdasia'\textomega
  \~>\textomega
  \~<\textomega
  \accpsili\textOmega
  \accdasia\textOmega
  \accpsili`\textOmega
  \accdasia`\textOmega
  \accpsili'\textOmega
  \accdasia'\textOmega
  \~>\textOmega
  \~<\textOmega
}}
\subsection{\ensuregreek{
  \accvaria\textalpha
  \accoxia\textalpha
  \accvaria\textepsilon
  \accoxia\textepsilon
  \accvaria\texteta
  \accoxia\texteta
  \accvaria\textiota
  \accoxia\textiota
  \accvaria\textomicron
  \accoxia\textomicron
  \accvaria\textupsilon
  \accoxia\textupsilon
  \accvaria\textomega
  \accoxia\textomega
}}
\subsection{\ensuregreek{
  \accpsili\textalpha\ypogegrammeni
  \accdasia\textalpha\ypogegrammeni
  \accpsili`\textalpha\ypogegrammeni
  \accdasia`\textalpha\ypogegrammeni
  \accpsili'\textalpha\ypogegrammeni
  \accdasia'\textalpha\ypogegrammeni
  \~>\textalpha\ypogegrammeni
  \~<\textalpha\ypogegrammeni
  \accpsili\textAlpha\ypogegrammeni
  \accdasia\textAlpha\ypogegrammeni
  \accpsili`\textAlpha\ypogegrammeni
  \accdasia`\textAlpha\ypogegrammeni
  \accpsili'\textAlpha\ypogegrammeni
  \accdasia'\textAlpha\ypogegrammeni
  \~>\textAlpha\ypogegrammeni
  \~<\textAlpha\ypogegrammeni
}}
\subsection{\ensuregreek{
  \accpsili\texteta\ypogegrammeni
  \accdasia\texteta\ypogegrammeni
  \accpsili`\texteta\ypogegrammeni
  \accdasia`\texteta\ypogegrammeni
  \accpsili'\texteta\ypogegrammeni
  \accdasia'\texteta\ypogegrammeni
  \~>\texteta\ypogegrammeni
  \~<\texteta\ypogegrammeni
  \accpsili\textEta\ypogegrammeni
  \accdasia\textEta\ypogegrammeni
  \accpsili`\textEta\ypogegrammeni
  \accdasia`\textEta\ypogegrammeni
  \accpsili'\textEta\ypogegrammeni
  \accdasia'\textEta\ypogegrammeni
  \~>\textEta\ypogegrammeni
  \~<\textEta\ypogegrammeni
}}
\subsection{\ensuregreek{
  \accpsili\textomega\ypogegrammeni
  \accdasia\textomega\ypogegrammeni
  \accpsili`\textomega\ypogegrammeni
  \accdasia`\textomega\ypogegrammeni
  \accpsili'\textomega\ypogegrammeni
  \accdasia'\textomega\ypogegrammeni
  \~>\textomega\ypogegrammeni
  \~<\textomega\ypogegrammeni
  \accpsili\textOmega\ypogegrammeni
  \accdasia\textOmega\ypogegrammeni
  \accpsili`\textOmega\ypogegrammeni
  \accdasia`\textOmega\ypogegrammeni
  \accpsili'\textOmega\ypogegrammeni
  \accdasia'\textOmega\ypogegrammeni
  \~>\textOmega\ypogegrammeni
  \~<\textOmega\ypogegrammeni
}}
\subsection{\ensuregreek{
  \u\textalpha
  \=\textalpha
  \accvaria\textalpha\ypogegrammeni
  \textalpha\ypogegrammeni
  \accoxia\textalpha\ypogegrammeni
  \~\textalpha
  \~\textalpha\ypogegrammeni
  \u\textAlpha
  \=\textAlpha
  \accvaria\textAlpha
  \accoxia\textAlpha
  \textAlpha\ypogegrammeni
  \accpsili{ }
  { }\prosgegrammeni
  \accpsili{ }
}}
\subsection{\ensuregreek{
  \accperispomeni\textcompwordmark
  \"\~{ }
  \accvaria\texteta\ypogegrammeni
  \texteta\ypogegrammeni
  \accoxia\texteta\ypogegrammeni
  \~\texteta
  \~\texteta\ypogegrammeni
  \accvaria\textEpsilon
  \accoxia\textEpsilon
  \accvaria\textEta
  \accoxia\textEta
  \textEta\ypogegrammeni
  \accpsili`{ }
  \accpsili'{ }
  \~>{ }
}}
\subsection{\ensuregreek{
  \u\textiota
  \=\textiota
  \`"\textiota
  \'"\textiota
  \~\textiota
  \~"\textiota
  \u\textIota
  \=\textIota
  \accvaria\textIota
  \accoxia\textIota
  \accdasia`{ }
  \accpsili'{ }
  \~<{ }
}}
\subsection{\ensuregreek{
  \u\textupsilon
  \=\textupsilon
  \`"\textupsilon
  \'"\textupsilon
  \accpsili\textrho
  \accdasia\textrho
  \~\textupsilon
  \~"\textupsilon
  \u\textUpsilon
  \=\textUpsilon
  \accvaria\textUpsilon
  \accoxia\textUpsilon
  \accdasia\textRho
  \`"{ }
  \'"{ }
  \accvaria{ }
}}
\subsection{\ensuregreek{
  \accvaria\textomega\ypogegrammeni
  \textomega\ypogegrammeni
  \accoxia\textomega\ypogegrammeni
  \~\textomega
  \~\textomega\ypogegrammeni
  \accvaria\textOmicron
  \accoxia\textOmicron
  \accvaria\textOmega
  \accoxia\textOmega
  \textOmega\ypogegrammeni
  \accoxia{ }
  \accdasia{ }
}}

\section{Makeuppercase}

According to Greek typesetting conventions,
diacritics (except the dialytika) are dropped in ALL CAPS.

However, \verb|\Makeuppercase| is not supported in PDF-strings, so we
do not need to care for this.

\section{Conclusion}

For Greek text parts in section headers use either literal Unicode
characters%
\footnote{Pre-composed Unicode characters must be used for multi-accented
letters or non-standard accents. Combining Unicode characters do not work
with inputenc and 8-bit LaTeX – this is a general restriction.} or macros.
For proper kerning in the main document, combine this with the
\verb+\textgreek+ or \verb+\foreignlanguage{greek}+ macros.

\end{document}