I noticed there're tags that are actually the singular and plural forms of the same term, e.g. and , and I guess most of them should be merged. Here're some possible candidates (tag counts are as of 7/17):

Edit: grouped tags by count and sorted alphabetically.

> 1000:

500 - 1000:

100 - 500:

< 100:

  • Which would you prefer, singular, or plural? Commented Jul 17, 2009 at 22:23
  • 8
    Plural, definitely. Commented Jul 17, 2009 at 22:36
  • 3
    Let native speakers choose (I'm not one).
    – Helen
    Commented Jul 17, 2009 at 22:38
  • 2
    I was going down the list and lost it at vector/vectors. "What's my vector, Victor?" Classic. +1 just for that. Another +1 if I could give it for the good idea.
    – Eric
    Commented Jul 17, 2009 at 22:56
  • 18
    Common sense, please. Keywords should not be pluralised. Concepts probably should. And certain words need to be left alone because pluralising them would change the meaning. Commented Jul 21, 2009 at 0:31
  • 8
    I don't get it. What's the argument for pluralizing these?
    – Shog9
    Commented Aug 4, 2009 at 17:53
  • 1
    @abatishchev See meta.stackexchange.com/questions/135985/… for a more up-to-date list. Since such tag pairs can only be created by moderator intervention now, that list should be complete. And please update it if you clean up a pair. Commented Aug 3, 2012 at 14:48
  • @Gilles: Sure, thank you! Commented Aug 3, 2012 at 14:52

12 Answers 12


This is a tough call. Tags that are clearly intended to be keywords should be singular (foreach, static, array, etc.)--foreachs makes no sense. However, concepts should be plural (loops, types, arrays, etc.). So, what do you do with tags like array? Some users are going to use the keyword array several times in a question, but really be asking about the concept arrays. Retagging this correctly would require reading and understanding the question. And you might get it wrong anyway. And you'd have to keep retagging.

What about conceptual tags like looping? Should be retagged as loops, right?

Maybe it's a matter of extending the tag matching logic to account for this. Ideally, there would be a way to indicate both. Entering array/s or array$ or similar would match both (or all variants). If i want to monitor all looping questions, i should just mark loop$ interesting and i get all questions marked loop, looping, for-loop, etc. Of course, i don't get foreach questions unless i mark for$ as interesting too.

Bottom line is that it would be nice to clean things up, but that's problematic. The real issue is matching tags.


Personally I'd favour the singular version over the plural generally speaking.

This might also be a good thing to factor out. Google for example is smart enough to realize plurals are equivalent to their singular form so there is no (or very little) difference between searching for "array" and "arrays".

We could pick a preferred one and make entering the plural form revert to the singular form (or vice versa if that's the consensus).


These are going to need to be done on a case by case basis. One reason why:

pipe = to send the output of one command as input to 
       another command. also, the vertical bar character.
pipes = Yahoo! Pipes

In some cases we could combine singular and plural versions into one tag like so:

group(s), value(s), type(s), etc.
  • 9
    +1 for the pipes example, but -1 for the "(s)" suggestion. so... net 0 from me. :)
    – Kip
    Commented Dec 25, 2009 at 4:21
  • 16
    Questions about Yahoo! Pipes should be tagged stackoverflow.com/tags/yahoo-pipes Commented Jan 3, 2010 at 17:22
  • I don't think most users of unix pipes etc will know to use the pipe tag rathern then the pipes tag. Commented Feb 1, 2010 at 15:26
  • 4
    If two very different phenomena are common in the programming sphere and differ by only an s at the end then that looks like a better disambiguation is needed. Banning the "pipe/pipes" tag and having unix-pipes and yahoo-pipes would work better, because people would be prompted into thinking about which tag to use. Commented Sep 21, 2011 at 23:56

I'd say definitely go towards plural tags if this gets put into place.

Although, we'd want to be careful to make sure that the merging of plurality doesn't remove some important distinction. For example, generic doesn't necessarily mean the same thing as generics (but it might in many cases).

  • 2
    What about something that is a keyword. e.g. string. strings is not the keyword, so would be incorrect. Commented Jul 21, 2009 at 0:29
  • @Colin Mackay: Maybe string-keyword? (By analogy with the if-statement, switch-statement etc.) There're already like-keyword, params-keyword and a few similar tags on SO.
    – Helen
    Commented Jul 23, 2009 at 17:19

I think it's not possible to change them all in batch...
A more case by case analysis will have to be made I guess.

In the Database - Databases case for instance there are only 14 plural... so I think changing those to Database might make sense... Although 14 is not that much to take a look at them individually as well...


I think the idea to merge them is good. I'm not entirely sure which way the community want it... any more feedback?


I suggest the tags should be declined/inflected so as to make the sentence “This is a question about ⟨tag⟩.” grammatically correct.

  • How could a singular/plural version make that statement grammatically incorrect? Could you give an example? Commented Oct 22, 2009 at 12:40
  • Going by that logic, they should all be pluralized: "This is a question about [strings, databases, tags, arrays]." Edit: and the more I think about it, the more I think that putting the tag into this sentence is a great way to decide.
    – s4y
    Commented May 5, 2010 at 1:22

Now that the tag synonyms feature was implemented, this can finally be easily handled by the community.

Although there seems to be no common/preferred form (e.g. arrays sing. but database pl.), I personally don't think it's much of the problem.


Here's one related retag request, library vs libraries:


Please weigh in with your opinion!


I made a couple Data Explorer queries that show most common tags with singular and plural version:

There are plenty of false alerts, but also plenty room for merging.


Here are some more tags


& and


  • best to post this as a separate question/retag request (tag it retag-request and discussion and the site name, eg, stackoverflow or serverfault or whatever). it's more likely to be seen by those who can perform the retag. Commented Mar 31, 2010 at 6:50
  • I thought so, but i saw so many questions on re tagging. I will post separate question. thanks :)
    – pramodc84
    Commented Mar 31, 2010 at 6:56

My suggestion, as a rule of thumb, would be that if one is more than twice as common as the other, go with the more popular one (because that's the one people will be more likely to use when writing questions in the future).

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