This is the only screen in the system that holds a conversation rather than a record, which is exactly why it is the one worth being careful about: in maintenance, the thing lost between two shifts is rarely the paperwork, it is the sentence somebody said out loud. So a handoff here is not delivered when it is written, it is delivered when a named person on the next shift accepts it, and one that turns over unaccepted is counted as dropped. Unread is stored per reader, because a single figure of twenty-three unread is not one fact, it is twenty-three different facts about twenty-three people added together wrongly. Presence is derived from a last-seen timestamp and decays after fifteen minutes, since somebody who shut a laptop never told us they left.