briefnote
nounUK /ˈbriːf.nəʊt/
US /ˈbriːf.noʊt/
A briefnote is a very short message you write to someone.
She left a briefnote on the fridge to remind him to buy milk.
OTHER MEANINGS
2. A quick written record of something you need to remember.
He kept a briefnote of the meeting time in his pocket.
3. A small piece of paper with a few words on it.
A briefnote slipped out of the book when she opened it.
4. A short official message sent between people at work.
The manager sent a briefnote to the team about the new schedule.