Background. For purpose of discussion, let A and B be tags, and let the goal be to convert B to A. There are two independent methods for doing this:

  1. (Looking forward): Creating a tag synonym A $\leftarrow $B ensures that in the future, any time that tag B is entered, it is silently converted to tag A.
  2. (Looking back): Merging tag B into tag A ensures that after the moment of merging, no more B tags exist, all having been converted to tag A.


  • Synonyms are not linked to 'interesting'/'uninteresting' filters, so a filter for B will not return questions labelled A after the above synonym is created
  • Synonyms are community-created: anyone with 1000+ rep can propose a synonym and if it gets 4+ votes it is automatically approved. Conversely, -2 votes automatically kill it.
  • Merging does not preclude new instances of B from appearing.
  • Merging is irrevocable: synonyms are not.

Discussion Ideally, synonyms do not require any moderator intervention. However, in our current state we don't have enough high rep users who participate at a meta level to create synonyms, and we haven't had any serious tag wars yet. However, we do want to clean up tags, just to make things a little more organized for searching/filtering.

while I can imagine situations where a merge of B to A need not be followed by creating the synonym A $\leftarrow$ B (B is a spam tag and we don't want to clutter the tag synonym list), I suspect that for a while, we will want to do both merging and synonyms together.

Proposed policy: merge+synonym

  1. Someone creates a RETAG request
  2. If a request gets at least T votes, then someone should flag the post for moderator attention and a moderator can create the synonym AND merge prior tags.

And T = 4.

We can revisit this later on if needed.

  • $\begingroup$ Sounds good, but what about the "remove cs. prefix" proposal + related changes; should we create a lot of retag requests for those? $\endgroup$ Commented Sep 7, 2010 at 10:04
  • $\begingroup$ I think we can go ahead with those. I've been doing them slowly just to make sure nothing breaks. No need to file retag requests $\endgroup$ Commented Sep 7, 2010 at 16:13

1 Answer 1


As explained in Suresh’s post to another discussion, some tag synonyms are created without their master tags being created. However, I think that some reconsideration is desirable because creating a tag synonym whose master tag does not exist in the system seems to have caused two problems.

  1. Some tag-related pages are Not Found. See comments to Suresh’s post.
  2. Users with rep less than 200 cannot tag his/her own question with either the older tag or the newer tag until some user with rep ≥200 uses the newer tag, even if the older tag is in use. See a note and comments in a question by Zack (but let’s avoid discussing about the issue on the question page).

Judging from how the feature of tag synonyms was requested on meta.stackoverflow.com, it seems to me that a tag synonym is supposed to be created when the master tag is already in use. Therefore, it is understandable that the system behaves oddly if the master of a tag synonym has not been created.

  • 1
    $\begingroup$ How about this then. We can do merges first followed by synonyms for now $\endgroup$ Commented Sep 21, 2010 at 2:10
  • $\begingroup$ @Suresh: Merging followed by creating synonyms sounds good if it is not too troublesome for you. $\endgroup$ Commented Sep 21, 2010 at 2:23
  • $\begingroup$ I did a whole round, including crypto and distributed comp. I'll wait for a few more to pile up before doing the next batch. $\endgroup$ Commented Sep 21, 2010 at 4:39
  • 2
    $\begingroup$ @Suresh: Thanks! $\endgroup$ Commented Sep 21, 2010 at 12:37

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .