The absence of a record can reveal the priorities of the recordkeeper.

What is not written down tells you what the person keeping the record did not consider worth keeping. That is often more revealing than the contents, since it maps the boundary of what counted as important at the time, and that boundary was rarely stated explicitly.

With any archive or account, ask what you would expect to find and then notice what is not there. Whose names, which events, what kinds of detail. The absences form a pattern, and reading the pattern is usually the fastest route to understanding whose account you are actually holding.