In vim, the filetype occasionally is set to a value that auto-populates formatoptions with r and o, two features that I do not like.
r
o
Modifying @sergio's answer slightly, you could use
autocmd Filetype * set fo-=r fo-=o
in your vimrc.
This removes 'r' and 'o' from 'formatoptions' whenever the filetype is set.
(Note that filetype detection has to be on, which can be set by :filetype on.)
:filetype on