Final pg_dumpall should happen in Single-User-Mode

I did a stupid mistake. I run the final pg_dumpall without switching to single-user-mode first.

With "final" I mean that the dump should be transferred to a different machine. After the dump
the old machine was shut down forever.

My mistake was that I stopped the services, but one process was still alive and this process
inserted to the database after pg_dumpall has started.

I guess I am not the first one who did this stupid mistake.

What do you think? Wouldn't it be polite to add a note about this topic to the docs?

Here are the docs for pg_dumpall: https://www.postgresql.org/docs/current/static/app-pg-dumpall.html

How could the wording look like? I am not a native speaker ....

Or do you have a better/different idea?

Regards,
Thomas Güttler

--
Thomas Guettler http://www.thomas-guettler.de/
I am looking for feedback: https://github.com/guettli/programming-guidelines