Annotation has properties anncoords and xyann which do not have any docstring. Not sure if this shall be part of this PR, but it would be good to document those.

I've added docstrings for anncoords and xyann. It's unfortunate that they have a different name than the corresponding constructor parameters. But that would be something for another PR.

See also #12144 re: mismatched names in constructor.

I've added docstrings for anncoords and xyann.

I don't see any change to the previous version.

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

$ git checkout v3.0.x
$ git pull

2. Cherry pick the first parent branch of the this PR on top of the older branch:

$ git cherry-pick -m1 7bcf6186e9420608ab60ea36b76f9a295aa4ea8a

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

$ git commit -am 'Backport PR #12214: Improve docstring of Annoation'

4. Push to a named branch :

git push YOURFORK v3.0.x:auto-backport-of-pr-12214-on-v3.0.x

5. Create a PR against branch v3.0.x, I would have named this PR:

"Backport PR #12214 on branch v3.0.x"

And apply the correct labels and milestones.

Congratulation you did some good work ! Hopefully your backport PR will be tested by the continuous integration and merged soon!

If these instruction are inaccurate, feel free to suggest an improvement.

This was tagged with v3.0.x. So when merging, it tried to autobackport to that branch. I resolved the conflict (which was a single empty line (??)), and created #12214, but does this now still need to go to v3.0.0-doc? Should it have been tagged with v3.0.0-doc instead?

Changes in .py files do not belong on the -doc branches as they have no effect on the resulting doc rebuilds.