Advised to be in underwear? (7)
I believe the answer is:
briefed
'advised' is the definition.
The definition and answer can be both to do with communicating as well as being past participle verbs.
Perhaps they are linked in a way I don't understand?
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for briefed that I've seen before include "Prepared" , "Instructed in advance" , "Informed of the facts" , "Advised or instructed, like barrister" .)