Comments attached to messages

[stasm]

Is your feature request related to a problem? Please describe.
Besides the source text, message typically have a lot of metadata about them: comments explaining the context and the purpose, clarifying vocabulary and expectations about the translations, and types of interpolated variables. The metadata is typically used by CAT tools to aid translators. it is also usually not relevant to the act of formatting the message at the runtime.

Describe the solution you'd like
Formalize how this metadata is stored in the data model and in the syntax.

Describe why your solution should shape the standard
CAT tools will benefit from the standard defining how this metadata is stored.

Additional context or examples
Fluent has three types of comments: message comments, group comments and resource comments. Message comments start with a single # and must be written on the line above the message id. See https://projectfluent.org/fluent/guide/comments.html. Example:

# Variables:
#   $extension (String) - file extension (e.g .TXT)
applications-file-ending = {$extension} file

[romulocintra]

This is completely needed, just wondering how we can make it work independently of resource format.

[mihnita]

I would expand this to more than messages.

I would propose:

1. Attach "metadata" to X (X is TBD)
   Not only comments, but also examples, links to screenshots, directives about the maximum length of the messages, etc.

2. Places to attach metadata to (the X above)

• groups of messages
• messages
• sub-messages (the feminine or the linux or the spoken variant of the message)
• placeholders

[aphillips]

See comments elsewhere, such as #40. This would be in-scope for a resource file format working group.

[aphillips]

Closing resolve-candidates per discussion in 2023-07-24 call