schemas and system tables

On Wed, 6 Aug 2003, Merlin Moncure wrote:

Is it feasible and/or advantageous to move all the system tables to a
system schema (to "system" or "pg_system")? This seems a much more
natural place for this type of information. This would remove the
artificial 'pg_' restriction on class names and simplify the overall
system a little bit. Just a thought.

I believe 7.3 already did this with pg_catalog.