Sure, though adding in note is a kind of signaling -- a social mechanism that helps teams come together. If someone is working as a contractor, is relatively isolated from the team, then there probably won't be a need or even a desire for the contractor to add notes to the client's management system, for the sake of signaling to the in-house development team. On the other hand, some sort of notes tend to make many non-technical clients feel better and be on top of things. (And some people are confused by signaling; a good communicator would be able to suss that out).