Where to document system views?

I have noticed that there is a nearly total lack of documentation of the
various predefined system views, which as of 7.2 include:

pg_indexes
pg_rules
pg_stat_activity
pg_stat_all_indexes
pg_stat_all_tables
pg_stat_database
pg_stat_sys_indexes
pg_stat_sys_tables
pg_stat_user_indexes
pg_stat_user_tables
pg_statio_all_indexes
pg_statio_all_sequences
pg_statio_all_tables
pg_statio_sys_indexes
pg_statio_sys_sequences
pg_statio_sys_tables
pg_statio_user_indexes
pg_statio_user_sequences
pg_statio_user_tables
pg_stats
pg_tables
pg_user
pg_views

The lack of docs for the pg_stat* stuff can be blamed on Jan and me,
but the other ones are of longer standing. My current thought is to
add a section somewhere that describes these views, but where? I don't
think it's quite right to document them under the System Catalogs
chapter of the Developer's Guide, since they're all intended for use
by ordinary users and dbadmins; the system itself doesn't use them.
Thoughts?

regards, tom lane