BUG #1648: ISO Year ignores time zone?

The following bug has been logged online:

Bug reference: 1648
Logged by: Nicholas Vinen
Email address: hb@pg.x256.org
PostgreSQL version: 8.0.1
Operating system: Gentoo Linux
Description: ISO Year ignores time zone?
Details:

rt3=# SELECT to_char(timestamp with time zone '2003-12-31 14:44:44-08', 'Mon
IYYY');
to_char
----------
Dec 2004
(1 row)

rt3=# SELECT to_char(timestamp with time zone '2003-12-31 14:44:44-08', 'Mon
YYYY');
to_char
----------
Dec 2003
(1 row)

Is that correct? It confused me... there doesn't seem to be a description in
the documentation which mentions IYYY what exactly an ISO year is...