I'm a bit prone to the out of place joke when people are being serious. But not in code. There is no humour in my code. Not even the odd pun. When something accidentally funny or ambiguous emerges I scrub it out. It feels like a sacred duty to make it as clear and concise as I can, and humour always detracts from that. Same goes for issues, etc. It just lowers the signal to noise ratio, when figuring this stuff out is tough enough anyway.