Obviously, we only need a single tag referring to the init file. Currently, there are several questions using dotemacs (which is a fine name), and one using init (which is less fine, but it might be referring to "initialization" instead of init file, it's hard to say).
Other perfectly valid names for this tag would be .emacs, init.el or init-file.
Do we have a preference either way?
The tag should be init-file. That is how Emacs itself refers to it, in (emacs) Init File.
That node explains what it is, and the fact that it can be ~/.emacs, ~/.emacs.el, or
~/.emacs.d/init.el.
(And for older Emacs versions the last of these is not a possibility. But it is still called the "init file", and the manual node is still Init File.)
I strongly dislike the name dotemacs. Is that pronounced dote-max? Names made of several words should have a separator between the words: dot-emacs (like on Stack Overflow). It's strange to write it that way rather than .emacs.
While .emacs has Emacs tradition for it, newer users might only know .emacs.d/init.el. Furthermore, .emacs has a risk of being used as a generic tag (“well, my question is about Emacs, so I'll use the tag that looks like ‘emacs’)”.
The manual section about the topic is called “The Emacs Initialization File”, or “Init File” for short.
So I favor initialization or init-file (or init-files to include the system initialization files?), with .emacs and dot-emacs as synonyms.
Thinking about it some more, I fear that .emacs or dot-emacs will be abused as “I want to put something in my .emacs to solve my problem”. That's an argument against having a tag that means “user initialization file”. Questions that are genuinely about `.emacs (like What should/shouldn't I do when keeping .emacs and .emacs.d in version control? or "Symbol's value as a variable is void: defun" when reloading .emacs?) can use the more general tag initialization.
emacs vs emacs -q vs emacs --batch for example) are only indirectly about the init-file as opposed to about how emacs initializes itself.
Commented
Sep 29, 2014 at 18:47
I like init-file, it's generic and it's clear of what is referring to.
Since this site is not only for GNU Emacs, using ".emacs" or "dotemacs" is simply inappropriate since XEmacs only supports it for compatibility purposes.
I definitely vote for the use of init-file in preference to all the others. But I also agree with Gilles that there's a risk this will end up being abused since most questions are likely to be about configuration of Emacs, and hence relate to what to write in the init file.
I would prefer dotemacs to the others.
It reflects both the ~/.emacs,~/.emacs.el as well as the folder ~/.emacs.d/init.el approach while init and init-el feel less precise for this purpose.
init could however be used to point to init related questions (e.g. How to change default minibuffer message?). This can be solved either in Customize or through initialization file changes, yet deals specifically with emacs initialization.
Following the other answers I have to revise my opinion.
dot-emacs or .emacs (to avoid ambiguity for dotemacs) or init-file seem best to me. Even though .emacs is deprecated for .emacs.d\init.el (or at least the latter is preferred) it is still part of the name for the init-file so could be applicable.
Other options still feel potentially ambiguous to me.
.emacs, but I'd assume many would find that weird. Of course it could be made a synonym..emacs(unless you only know.emacs.d/init.el)? Nowdotemacs, that's a really weird name.dotemacscame from the renaming of the hidden.emacsfiles to make them accessible on the web.