DB2 NULL Comparisions

Need a reminder as I have to compare Nullable date with Nullable date columns:

Comparing two columns using a normal equal comparison (COL1 = COL2) will be true if both columns contain an equal non-null value. If both columns are null, the result will be false because null is never equal to any other value, not even another null value.

Select
 case when null = null then 1 else 0 end as NULLNULL
 ,case when null = 'a' then 1 else 0 end as NULLVALUE
 ,case when null = 1 then 1 else 0 end as NULLVALUE
from sysibm.SYSDUMMY1

NULLNULL|NULLVALUE|NULLVALUE3
0|0|0