I'm not sure about the standard, but I really like Oracle's notation for
foreign keys:
select a.item_number, b.group_code_description
from items a, group_codes b
where a.group_code = b.group_code (+);
Much better than
select a.item_number, b.group_code_description
from items a outer join group_codes b on a.group_code = b.group_code;
In fact, it's MUCH BETTER when you have to join several tables (one thing
PgSQL is very good at, by the way). In such cases, the seconde syntax
requires an unreadable lot of ()'s in the from clause.
Don't mean to throw away the standard though, but having Oracle's (+) syntax
around too would be a big help.