RMAN catalog question

For our RMAN configuration, we run a single database to store individual catalogs for each of our databases. We create a new users in this central database and dedicate each user for the catalog of each database in our environment. That way we have a 1 to 1 relationship between schemas(which store a catalog) and the databases we are backing up.

Do we have to be concerned about what version of Oracle this central database that stores all the individual catalogs is running? Does it always have to be running the highest version of Oracle that we run in our environment?

http://docs.oracle.com/cd/B28359_01/backup.111/b28273/compat003.htm#i634479

The matrix in the above link is not exactly clear to me. Does the version of the recovery catalog schema come from the RMAN client version used to execute the create catalog command, or the version of the database that is used to store the catalog?

Does anyone have any guidance on this?

Thanks in advance for your help.       

--
http://www.freelists.org/webpage/oracle-l