Questions about 9.0 release note

Hi, I have some questions about 9.0 release note.
I'd like to work for some of them if required. Comments welcome.

* Allow per-tablespace sequential and random page cost variables (seq_page_cost/(random_page_cost)) via ALTER
TABLESPACE... SET/RESET                 ^                ^
 
Are those parentheses around random_page_cost intentional?
They seems to mean just "(seq_page_cost and random_page_cost)".

* EXCLUDE constraints has no tags to be linked.
The item in release note is pointing the following page,
http://developer.postgresql.org/pgdocs/postgres/sql-createtable.html#SQL-CREATETABLE-DESCRIPTION
but the actual description about EXCLUDE constraints are in the subentry
of "Parameters" section. Can we add a tag to <varlistentry> for EXCLUDE?

* "EXCLUDE constraints" is not indexed from the Index page.
Should we have for it? Unique Constraints have a section for them:
http://developer.postgresql.org/pgdocs/postgres/ddl-constraints.html#AEN2431

Regards,
---
Takahiro Itagaki
NTT Open Source Software Center