What's your opinion on leaving funny notes in comments from time to time? Is it highly unprofessional or you don't mind them if they are sparse?

I found this on GitHub jebej/Schrodinger.jl

I think some swearing in comments is important

Keeps us from going insane

I beg for forgiveness from time to time.

Funny comments or jokes are ok, if your leaving them behind for a sense of humor or if its a difficult piece of code.

But I've seen code where there were swear words left behind. Like d&#k, f@_#... Things of the sort. That is very unprofessional and offensive.

As long as it doesn't detract from the informativity of the comment — and yeah I wouldn't use the same language as you might use on devRant.

Coding is fun enough at it is - so keep the comments clean.

Leaving something that turns out to be funny later because of frustration, empathy or other emotion is ok. Swearing is borderline, but I personally would get it. Leaving them to force being funny or to provoke the person doing code review, that's just dumb.

Don't force it, use it where it makes sense and where it helps understand the code better

My senior developer (usually extremely strict on clean code and documentation) lost his cool when we had to refactor a certain calculation application to make the same rounding mistakes as the excel sheet they used before. He made a new module that uses the old calculation core and adds the rounding mistakes. Each time he documented one of the rounding method he added something like "this methods calculates xy and adds the stupid rounding mistakes from the excel sheet that must have been clearly made by some idiot."
I understand him tho. Even our project manager and PO did.