Who did what in here
Two people work in this office. Everything either of you does in a room is written down under your own name, in your own column, as it happens. Nobody can write a line in the other one’s column, and nothing here can be edited or deleted — that is what makes it a record rather than a list.
What was done is kept, not what was said. Asking Roz something is not an entry; the thing you asked her for becomes one the moment you tap Do it and it lands in a room. Reading a room is never an entry either. The last four hundred things each of you did are held, and older ones fall off the end.