The other day I heard that one of my colleagues had been “signed off”. As this was the first time I’d heard this expression in this context I wasn’t sure what to make of it. Later I discovered that she had been signed off by her doctor due to carpal tunnel syndrome and would be spending a week or two at home resting.

Have you heard this expression used in this way before?

I’ve heard of radio and television stations signing off at the end of the day, though many stations no longer do so as they broadcast 24 hours a day. I’ve also heard of projects, expenses and budgets being signed off.

There are a number of other English idioms involved signing here, including sign on, sign up (for), sign over and sign out. I suspect such expressions, and similar ones like get on/off/up/down, etc. might be quite tricky for learners of English.