Empty String Comparison Standard compliant?

Just a short question (PostgreSQL 7.3.4 on hppa-hp-hpux10.20, compiled by GCC 2.8.1) 

SELECT ('' > 'GDMF') ; SELECT ('GDMF' > '');?column? 
----------f
(1 row)
?column? 
----------t
(1 row)

Are these results standard compliant? 
Looks at least pretty reasonable to me. 
It's just because I have a DBMS here, where the results are vice versa. 

TIA. 

Regards, Christoph