With DIMDATA, you need to specify whether the variable is LOCAL or GLOBAL before you can setup the list - ie, something like :
GLOBAL demo[]
DIMDATA demo[],1.0
which makes typing it bit long-winded (and possibly prone to a Syntax Error if you forget the definition type).
It would be a bit more efficient to do something like :
GLOBAL DIMDATA demo[],1.0
that would be
DIMDATA GLOBAL arr[], 1,2,3
It works
I'm uncertain if there will be an strict-wrning, though.
Unfortunatey, you get a syntax error with that...