Similar to HTTP_451

HTTP 451

HTTP 403

HTTP 404

HTTP 503

Error message

Abort, Retry, Fail?

Guru Meditation

Linux kernel oops

Lp0 on fire

Not a typewriter

PC LOAD LETTER

Bad command or file name

Request for Comments

April Fools' Day Request for Comments

Internet Engineering Task Force

Character Generator Protocol

Daytime Protocol

Discard Protocol

Echo Protocol

Finger (protocol)

User Datagram Protocol

Trivial File Transfer Protocol