Code of Conduct

• I have read and agree to the GitHub Docs project's Code of Conduct

What article on docs.github.com is affected?

https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#custom-anchors

What part(s) of the article would you like to see updated?

Section "Custom anchors"

I don't necessarily want the section to be changed, but rather would like to know if custom anchors are really officially supported by GitHub-flavored Markdown.
#33531 which added this section seems to have been written by a non-GitHub employee, and also #33531 (comment) by a GitHub employee rather sounds like this is just describing the current behavior, without actually giving any guarantees.

For reference, GitHub's handling of custom anchors was changed in the past and did break custom anchors in multiple projects, see https://github.com/orgs/community/discussions/50962.

Additional information

No response