Docs for psql regarding default database name are incorrect

The documentation for psql saith:
https://www.postgresql.org/docs/devel/app-psql.html

The default user name is your operating-system user name, as is the default
database name.

The default database name is the same as the user name chosen for the
connection attempt. Thus if one does "postgres~ psql -U davidj" the
attempted database name will be davidj, not postgres even though the latter
is the operating-system user name in effect.

The documentation for -U doesn't mention this changing of the attempted
connect-to database. It is not possible to specify a user name without a
database name explicitly given for psql unless one uses -U.

Thus at minimum the above needs to read:

The default user name is your operating-system user name. The default
database name is the same as the resolved PostgreSQL user name.

Maybe change the description for -U:

"...of course)." This also changes the default database name.

The parameter dbname in libpq got the memo:
https://www.postgresql.org/docs/devel/libpq-connect.html#LIBPQ-CONNECT-USER

The database name. Defaults to be the same as the user name.

David J.