Question on comment

I note from <URL:http://www.postgresql.org/docs/user/sql-comment.htm>
that 'comment on' is now implemented in PostgreSQL.  The documentation
do not specify when this statement became available.  I'm currently
using v6.5.3 and it is not available there.  I suggest adding
information in the documentation about when (ie. which version) a new
statement was implemented.  Do I have to move to 7.x to get this
feature?

The documentation do not mention any tools for extracting these
comments into text, HTML or any other format.  Do these exist?  Is it
possible to extract these comments using some SQL query?
--
##>  Petter Reinholdtsen  <##  |  pere@td.org.uit.no