There appear to be quite some tags that represent a file extension:

  • Some have a dot (, ), while others don't (, ).

  • A lot of these don't seem to have much questions in them.

  • There might be occasions where the file extension is used instead of the program.

  • Sometimes the tag is ambiguous and the three letter word could represent a program as well.

So, some questions related to them:

  • Are file extension tags welcome?

  • Should they be with or without a dot?

  • Should we add something in front or behind them to clarify that these are extensions?

    eg. vs vs

What do you think about these tags? How should we make them more consistent and/or group them?

  • 1
    Do note that those file extensions seem to be rarely used Mar 8, 2012 at 1:24
  • A user is going to try and toss those in when dealing with the "file" that has that extention. If they do not know "how to open?" , "what program?" , "why an error with .doe?". Does that need a Tag? or would the "files" tag work? If the user knows the program or programs, they might say "problem with Cold Fusion Markup Files" Tag Cold Fusion & Files . So if that was a few of the scenarios for the users , would raw file extentions be needed? It is either all they have, or they Know enough to talk about the program or file?
    – Psycogeek
    Mar 8, 2012 at 2:47
  • With .dot for the user who doesnt know , without dot for programmer and tech person, who should be able to speak in whole words? Add something to the front, then try to find the tag by typing in .ext or ext only ? Try it tag search, type first 3 letters. So any identifier beyond the intent of the search is After not before.
    – Psycogeek
    Mar 8, 2012 at 2:57
  • @Psycogeek: Searching with an identifier before works just fine, eg. conversion Mar 8, 2012 at 3:03
  • Do tag descriptions work? User begins to ask question, upon entering a .ext into tag entry, user finds out the tag extention, like they could have done on google. Description is all they needed. with hundreds of properly described .ext It could replace looking them up on google?
    – Psycogeek
    Mar 8, 2012 at 3:08
  • @TomWijsman your right, no wonder. Fake asking a new question, in the tag entry type EXT (no dot) you get a very limited view of the whole tag set, and EXT3 and EXT2 are not even there yet.
    – Psycogeek
    Mar 8, 2012 at 3:14
  • most common extentions in Tags here do not have the .dot. The reason a person puts the dot on the front when doing a google, is because that is the only way your going to start searching for the extention, otherwise the search is for anything.
    – Psycogeek
    Mar 8, 2012 at 3:43
  • @Psycogeek Note that when searching e.g. for .mov in Google, the top results don't have the dot. Google doesn't care.
    – Daniel Beck Mod
    Mar 8, 2012 at 7:15
  • 1
    The most popular are pdf, (perhaps partially) php, mp3, zip, tar. None of them with dot. The problem is, that the file extension is the same as the name or acronym of the format.
    – Daniel Beck Mod
    Mar 8, 2012 at 7:20
  • I've been meaning to ask about this as well. Hm. maybe we should get rid of the dot-notation. In many cases, that just works. Let's find those that would be ambiguous. I don't think that's too many.
    – slhck
    Mar 8, 2012 at 9:28
  • @DanielBeck and .mkv .xvid .dvix , with or without the dot, if a person goes to look for "what that applies to" "what it is" they find it. when tagging here or searching for the tag dot or no dot changes it. both do not exist in all situations.
    – Psycogeek
    Mar 8, 2012 at 15:35
  • Mov, .mov , mov-extention ? what does that mean? and why Mov-files? Are we going to have Quicktime , Quicktime-container , Quicktime-files Quicktime-converter Mov-converter Mov-files .Mov are quicktime-files :-) the endless creation of tag by these combos can be done by the user. Quicktime is NOT all .mov Quicktime can be .mp4 , but .mp4 is not quicktime. But the Combination by the USER. [Quicktime][Files] , [Quicktime][mov] , [mov][extention?] , [Mov][mp4] Even, Add more junk to everything and we set up having more items.
    – Psycogeek
    Mar 8, 2012 at 15:53

2 Answers 2


Are file extension tags welcome?

If the question is about a specific file format, I think it's perfectly fine to use a file extension tag. I don't see a better replacement for , or . You could use a different tag, but it would be longer, and without a good reason.

Should they be with or without a dot?

The extension is the part without the dot. You can say "the .docx files" to mean "the files with extension docx," but the dot is not normally considered part of the extension.
To notice that, for example, is not a tag about files using "profile" as extension; ".profile" is the name of a file used from Bash, and the dot at the beginning makes the file "hidden" as they are not normally listed from ls (without a specific option).

Should we add something in front or behind them to clarify that these are extensions?

I don't think there is the need to clarify the tag is about an extension.


Okay. if I'm not wrong, there aren't a lot of these tags anyway. Just look at them sorted by name. Those with a dot will appear first.

Given that these are in a minority, we should just use the notation without dots. This will require less effort, and it makes the tags easier to find.

I don't think there will be any ambiguities, otherwise we'd have found them already.

Tags to keep:

Tags that can be renamed:

  • What is "direction" for a synonym ? How does that effect searching the tag, following the tag, using the tag in the question?
    – Psycogeek
    Mar 8, 2012 at 16:10
  • Files named bashrc have no special meaning. /etc/bashrc exists just by convention, and need to be manually included from e.g. ~/.bashrc. The synonym really should be reversed, as the tag is really about the dot-file .bashrc, similar to .bash_profile. Other than that, agreement.
    – Daniel Beck Mod
    Mar 8, 2012 at 16:42
  • 1
    @Psycogeek Direction says which tag is just a synonym, and which is the canonical name. Search for [.bashrc] and it's obvious, you just get redirected. The canonical name is also suggested when users type the synonym (or a prefix of it) in the tag box (try it with os-x), and if you actually enter a synonym, it will be replaced by the canonical tag name.
    – Daniel Beck Mod
    Mar 8, 2012 at 16:44
  • @DanielBeck so when it comes to dot or not, every extention that is in the tag system, could have a dot synonym, and the users would always be pushed over to the the SU defined tag. . The SU pattern would then be followed. About 1000 extention tags and 1000 dot synonyms would ever exist (long term), and the SU defined method would be used?
    – Psycogeek
    Mar 8, 2012 at 17:42
  • 1
    @Psycogeek Yeah, but why? Past use clearly indicates that file types/file extensions are 99% used without the dot. It's a total of 10 questions with the leading dot. Let's just rename these tags as proposed by slhck, and move on. There's also some nice consistency in using the dot for Unix dot-files, and not using it for file extensions.
    – Daniel Beck Mod
    Mar 8, 2012 at 18:10
  • @DanielBeck OK. I was just thinking if it solidified with both, it is done, it is not changed/added again (because both exist), and it lives forever.
    – Psycogeek
    Mar 8, 2012 at 18:14
  • 1
    I like the idea of making file extensions synonym of their products, if and only if it's a one-on-one mapping. Otherwise one could add references to the product tags in the tag wiki. I'm not a Linux guy, but isn't .bashrc a file on it's own instead of a file extension? Mar 8, 2012 at 20:05
  • 1
    @TomWijsman Yeah, it's a so-called "dotfile". It's not an extension, as you said.
    – slhck
    Mar 8, 2012 at 20:15
  • @slhck: Oh, right. That's why you want that one to include the dot. Misread... :( Mar 8, 2012 at 20:18
  • 1
    So let's make [mov] a synonym for [quicktime]. slhck, would this be correct? cc @TomWijsman
    – Daniel Beck Mod
    Mar 10, 2012 at 9:18
  • Yes, I think so. Haven't seen it used elsewhere without mentioning quicktime... Mar 10, 2012 at 10:29
  • @TomWijsman Files whose name starts with a dot are handled in a particular way: Normally, they are not listed with ls, except when you use a specific option for the command. It's a way to hide the file.
    – apaderno
    Mar 10, 2012 at 11:14
  • 1
    @kiamlaluno: I know that, but that doesn't hold up for .cfm and .mov though; which is why I explicitly listed those two. I'm just not sure whether specific names are files or extensions... Mar 10, 2012 at 11:27
  • @TomWijsman If there were a file whose name is .mov, that file would not be handled differently from the .profile file, from Bash (i.e. it would be considered an hidden file). To know if it's a file extension, or a filename, you need to see what the application using it is doing; if it looks for a file named .profile, then it's not an extension.
    – apaderno
    Mar 10, 2012 at 12:13

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