If you can, it’s a good idea to set up your .vimrc file using conditionals so that it’s compatible on all of the systems with which you need to work. Using one .vimrc file enables you to include it as part of a centralised set of dotfiles that you can keep under version control.

However, if on a particular machine there’s a special case which means you need to load some Vim directives for that machine, you can achieve this by way of a local Vim file kept in .vimrc.local, only on one particular machine, and detecting its existence before attempting to load it in your master .vimrc file with the following stanza:

if filereadable(glob("~/.vimrc.local")) 
    source ~/.vimrc.local
endif

As an example, on one of the nameservers that I manage, I wanted to make sure that the correct filetype was loaded when editing zone files ending in .nz or .au for New Zealand and Australian domains. The following line in .vimrc.local did the trick:

autocmd BufNewFile,BufRead *.au,*.nz set filetype=bindzone

If the .vimrc.local file doesn’t exist on any particular machine, Vim will simply not attempt to load it on startup.

Besides machine-specific code, this kind of setup may be advisable if you keep secret or potentially sensitive information in your .vimrc file that you wouldn’t want published to a public version control tracker like GitHub, such as API keys, usernames, machine hostnames, or network paths.