Saying "RIP" is not only lazy, it's down right insulting.
Make an effort will ya, and write the whole thing ffs.
"Rest in peace"
Takes one second longer and looks 100 times better.
I don't like laziness, I think "R.I.P" is downright lazy and rather insulting to the dead person.
If you care, make the effort to type out the whole sentence, in somewhat respect.