Opinion wanted on UUID/GUID datatype output formats.

Folks,

I would like to have your opinion on the following:

At this moment we (almost) have a uuid/guid datatype.
As suggested in earlier discussion we provide a raw/plain output of the
uuid type:

devdb=# select * from tbluuid;
pk |
----------------------------------+
6b13c5a1afb4dcf5ce8f8b4656b6c93c |
01e40a79b55b6e226bffb577e960453d |
(2 rows)

I was wondering if we want to have a formatting function to be able to
provide other common formats of the uuid/guid?

something like:

select format_uuid(mypk,'format2') from tbluuid;
and then get: 6b13c5a1-afb4-dcf5-ce8f-8b4656b6c93c

or

select format_uuid(mypk,'format3') from tbluuid;
and then get: {6b13c5a1-afb4-dcf5-ce8f-8b4656b6c93c}
(which would be MSSQL compatible)

Do we want such a function added to the core or we let the application
handle the formatting if ever needed.

What do the PostgreSQL masters think? :)

Regards,
Gevik.