it works, but is it legal to separate schema/table/field references using spaces

Hi,

Just something I noticed to 'simply work':

db=# select avg(pg_catalog . pg_stats . avg_width) from pg_stats;
avg
---------------------
10.6654945054945055
(1 row)

It seems that all whitespace between schema/table/field references is ignored?

Not saying this is a bad thing per se, it just surprised me and made me wonder
if this intended to work like this and/or legal per sql-specs ;)

db=# select version();
version
------------------------------------------------------------------------
PostgreSQL 8.2.4 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.4.3
(1 row)

--
Best,

Frank.