I agree: it's absolutely an in-group joke. Maybe not joke, but a cutesy in-group way of expressing something. Certainly someone who gets it will, well, get it

I agree: it's absolutely an in-group joke. Maybe not joke, but a cutesy in-group way of expressing something. Certainly someone who gets it will, well, get it. But in general it seems like a lot of effort in most cases to gauge whether or not the recipient will understand at the level you hope. Even the UDP example could be misunderstood by someone who is well-versed. Unreliable? A good low-level thing to build stuff on top of? These are both plausible meanings, but would convey very different things. Better to just use clear language.