"Was he under section?"
In a British crime drama, two police officers are talking about a mentally ill patient being a resident at a mental hospital when one of them asks the question, "Was he under section?"
What does that mean??
Seems there are a lot of British expressions I can't quite understand
or even find on the internet. It's so frustrating.
Can anyone help? It'd be really appreciated!!!!!!!
Thanks in advance.
Was the phrase followed by a cardinal number?