Where can I find .mpdignore documentation with examples?

[Kurantje]

I am looking for a way for mpd to ignore everything except files with mp3 extension when scanning/updating the database
In the documentation I found .mpdignore with rules like .opus and 99 to exclude files with .opus extension or starting with 99
I am looking for an example rule how to not ignore a pattern. Does that exist?
With ChatGPT I get proposals to use:

# Ignore everything by default
*
# But do not ignore MP3 files
!*.mp3

However, this does not do what I want: the * rule indeed ignores everything, but the !*.mp3 rule does not result in my mp3 files to be included in the database.
Is the !*.mp3 rule actually supposed to work? Or is ChatGPT hallucinating?

[MaxKellermann]

Hallucination.

[Kurantje]

Thanks for clarifying