@Alyzande There's also a lot of nuance in the 4xx codes:

400: YOU fucked up
401: I don't know you, fucker
402: WTF is wrong with MEβ€½
403: Fuck you!
404: Fucks not given
405: We don't do that kind of fucking
406: What The Fuck?
407: Fuck you and the horse you rode in on!
408: I'm sorry, WTF did you want again?
409: I'm sorry Dave, I can't fucking do that
410: Fuck this shit
411: Your size makes you unfuckable
412: Fuck you and your weird requirements!

411 being the rudest.

@riskable
Everyone keeps forgetting error code 420 though. It's purely internal and reads "Fuck *coughing* πŸ€·β€β™€οΈ".
However as of RFC 720, the internal state of the server is very much not caring and could not give a fuck, so this code is never actually transmitted.
@Alyzande @daswarkeinhuhn