- What are tag synonyms?
- How can tag synonyms be distinguished from "real" tags?
- How are new tag synonyms created?
- Who can create tag synonyms?
- How can I delete/reverse/undo bad tag synonyms?
There's a lot of good info in the tag synonym announcement on the Stack Overflow blog.
What are tag synonyms?
A tag synonym is usually a tag that has exactly the same meaning as some other tag, such as algorithm and algorithms. In some cases, tags that are subsets of other tags will also be considered synonyms, such as java-se for java.
The system organizes tags in a master/synonym relationship. All uses of the synonym tag(s) for any given master tag are automatically converted to the master tag. So, users can enter a synonym tag when writing a question, but the master tag will be displayed when the question is loaded. Similarly, when users search for questions tagged with a synonym, a list of questions tagged with the master will be displayed.
A master list of synonyms is available at
How can tag synonyms be distinguished from "real" tags?
The system provides an autocomplete function for users entering or editing tags. Usually, tags that are in use on multiple questions show up with the number of times they've been used, e.g.
On the Tags list, under the "popular" tab, "real" tags are displayed with the most-used tags first. In case of tie, they are sorted alphabetically. Synonyms are each used zero times, so they show up at the end of the list (i.e. on the last several pages).
How are new tag synonyms created? Who can create tag synonyms?
Suggestions will be automatically approved when they reach a score of four, and automatically deleted when they reach a score of negative two.
The synonym admin panel is located at
If there aren't enough people aware of the tag synonym, of if you aren't sure whether the synonym is a good idea, open a discussion on your site's meta site, tagged discussion tags tag-synonyms (for questions about the synonyms on the meta site, add meta).
Existing questions are not automatically retagged when a tag synonym is created. Moderators have the ability to do this by "merging" the tags, but this is not (easily) reversible, and so should be used with caution. Editing a question tagged with a synonym tag does cause it to be replaced by the master tag.
How can I delete/reverse/undo bad tag synonyms?
Only moderators can correct a bad synonym. The only recourse is to post a question on your meta site explaining the problem with the synonym relationship. Use the tags discussion tags tag-synonyms (for questions about the synonyms on the meta site, add meta). Give the community a few days to show support or make alternate proposals. Once the discussion has settled, a moderator will perform what correction is he or she deems necessary given the discussion. (You may retag your question feature-request once you think the correct course of action has been determined. If there is still no moderator response after a couple of days, contact a moderator in chat.)