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## Output
```text
Comment for build stage or argument should follow the format: `# <arg/stage name> <description>`. If this is not intended to be a description comment, add an empty line or comment between the instruction and the comment.
```
## Description
The [`--call=outline`](https://docs.docker.com/reference/cli/docker/buildx/build/#call-outline)
and [`--call=targets`](https://docs.docker.com/reference/cli/docker/buildx/build/#call-outline)
flags for the `docker build` command print descriptions for build targets and arguments.
The descriptions are generated from [Dockerfile comments](https://docs.docker.com/reference/cli/docker/buildx/build/#descriptions)
that immediately precede the `FROM` or `ARG` instruction
and that begin with the name of the build stage or argument.
For example:
```dockerfile
# build-cli builds the CLI binary
FROM alpine AS build-cli
# VERSION controls the version of the program
ARG VERSION=1
```
In cases where preceding comments are not meant to be descriptions,
add an empty line or comment between the instruction and the preceding comment.
## Examples
❌ Bad: A non-descriptive comment on the line preceding the `FROM` command.
```dockerfile
# a non-descriptive comment
FROM scratch AS base
# another non-descriptive comment
ARG VERSION=1
```
✅ Good: An empty line separating non-descriptive comments.
```dockerfile
# a non-descriptive comment
FROM scratch AS base
# another non-descriptive comment
ARG VERSION=1
```
✅ Good: Comments describing `ARG` keys and stages immediately proceeding the command.
```dockerfile
# base is a stage for compiling source
FROM scratch AS base
# VERSION This is the version number.
ARG VERSION=1
```
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