Name column

I have just come across a weird thing. It works for any table and seems 
to be not documented.

SELECT c.name FROM (VALUES(1, 'A', true)) c;
SELECT c.name FROM pg_class c;

And it does not work in these cases:

SELECT name FROM (VALUES(1, 'A', true));
SELECT name FROM pg_class;

PostgreSQL 8.4.2 on x86_64-redhat-linux-gnu, compiled by GCC gcc (GCC) 
4.1.2 20071124 (Red Hat 4.1.2-42), 64-bit