I don't git it

Adding a tag to a git tree is not hard, as long as you know the secret parameters.

Deleting a tag is another story. Here's what you'd expect to work...

[dave@starbuck fb-3]$ git tag -d 6.x-3.0-RC9
Deleted tag '6.x-3.0-RC9' (was 9f9bd0f)

[dave@starbuck fb-3]$ git status
# On branch 6.x-3.x
nothing to commit (working directory clean)

[dave@starbuck fb-3]$ git push --tags origin
Everything up-to-date

[dave@starbuck fb-3]$ git pull
From git.drupal.org:project/fb
 * [new tag]         6.x-3.0-RC9 -> 6.x-3.0-RC9
Already up-to-date.

Despite the assurances "Deleted tag..." and "Everything up-to-date", you're just one git pull away from having the tag back!

Here's how you can actually delete it...

[dave@starbuck fb-3]$ git tag -d 6.x-3.0-RC9
Deleted tag '6.x-3.0-RC9' (was 9f9bd0f)

[dave@starbuck fb-3]$ git push origin :refs/tags/6.x-3.0-RC9
To yogadex2@git.drupal.org:project/fb.git
 - [deleted]         6.x-3.0-RC9

[dave@starbuck fb-3]$ git pull
Already up-to-date.

:refs/tags/... - how obvious!

Thanks to Nathan Hoad for providing the solution.

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