Default numeric: zoned or packed

I've read a lot of articles and threads (here or in archives) that
mention that if a number data type is left undefined, it will default to
Packed.
On our system, it defaults to Zoned.
Is there a system setting involved here?
 
I recently created a data structure that had file-defined fields (so I
only had the name of the field in the DS, no definition) and it
converted all my Packed numbers to Zoned (which of course caused my
calls to unprototyped programs to fail).
 
The solution I had was to explicitly define the numeric fields in the
data structure (which I don't like doing b/c now if one of those field
definitions changes, someone has to fix the data structure).  I
considered using ExtFld, but, near as I can tell, that only works with a
ExtName - and I don't want all the fields from that file in the data
structure.
 
Kurt Anderson
Application Developer
Highsmith Inc.
W5527 State Road 106, P.O. Box 800
Fort Atkinson, WI 53538-0800
TEL (920) 563-9571  FAX (920) 563-7395
EMAIL kjanderson@xxxxxxxxxxxxx