Currently, it seems to be used (very intermittently) for questions involving code which could be placed in a vimrc file, for questions for which the answer involves putting some code in your vimrc file, and for questions where the asker couldn't think of/be bothered to use more appropriate tags: https://vi.stackexchange.com/questions/tagged/vimrc
i.e. it has no meaning. This doesn't seem all that useful to me.
I'd be happy to help clean up its use, if I had a good idea of what the community thinks it should be used for.
Improved tag info for that tag would probably help, too.