In the documentation it says "DT, DO, DY and DZ do not accept numeric constants as operands."
So how do you use them? They are supposed to be used for putting in initialized data (as with DB, DW, and DD), but if they don't accept constants, then how do you use them. Sadly the documentation does not mention this, leaving the end user (like me) scratching his head, trying to figure out how to use them.