Lol I remember early in my career using "fuck" and "cock" a lot for debugging. Very quickly learned to not do that, I instead replaced it with "banana" for the most part
Nanny Ogg knew how to start spelling 'banana', but didn't know how you stopped.
IMPORTAAAAAAAAAAAAAAAAAANT
_F for functions.
_H for headers.
_V for fuck knows.
There are funnier ones but I am lazy. :P