pgdump question

Hi:
PGVERSION=7.2

I have a backup/restore question. Reading the manpages from pg_dump
I have noticed a reference to the -o qualifier for OIDS.. Following a
somewhat general model where an administrator is responsible for backups
and restores of the database, the admin may not know how an application
programmer uses postgres (oid reference for example)..

If the database backup uses the following call to pg_dump, is there
any information or object that is not in the backup where PGDB is the
name of the database, PGEXPORT is directory for the dump, and PGDB-DATE
is the pg_dump file name? The backup plan assumes all postgress on the machine
databases are included in the backup. Would for example groups be included
in the backup?

pg_dump -Ft -b -o $PGDB > $PGEXPORT/$PGDB-$DATE.pgtar

Ken Klatt