Filetype plugins for foo filetype are sourced in that order:
1. $HOME/.vim/ftplugin/foo.vim. Be careful with what you put in that file as it may be overridden by $VIMRUNTIME/ftplugin/foo.vim -- under windows, it'll be instead $HOME/vimfiles/ftplugin/foo.vim
2. $VIMRUNTIME/ftplugin/foo.vim. Like ev...
