KISS

From Encyclopedia Dramatica

Keep it simple, stupid! This term has a long and glorious history with the US military, and is usually referenced as KISS RuleZ. Things break when they get too complex anyway. Additionally there is a rich computer history of the term, especially (of late) in the UNIX world, whereas the rest of the world's code has come to be very tl;dr.

Gene Simmons after he retired.

Sample Usages:

If you don't KISS, don't bitch when nobody pays attention to you.

Holy hell, private, if you violated KISS any more I'd have to kick the shit out of you.