The /DEFINE compiler directive defines conditions for conditional compilation. The entries in the condition-name area are free-format (do not have to be left justified).
/DEFINE must be followed by at least one space, and then
the condition-name must be specified on the same line.
The remainder of the line must be blank. 
In fixed-form, /DEFINE must begin in column 7. 
/DEFINE cannot be specified within
a free-form statement.
However, between free-form statements, /DEFINE can begin in
column 7 or later. 