This Natural profile parameter specifies when work files are to be opened by Natural.
| Possible settings | ON | A work file is opened at the time when it is first
                           					 accessed by a given READ WORK
                                 					 FILEorWRITE WORK
                                 					 FILEstatement. This means that only those work files which
                           					 are actually accessed are opened, while the contents of unopened work files are
                           					 not deleted. | 
|---|---|---|
| OFF | All work files referenced in a Natural object are opened
                           					 when the execution of this object starts. (This may delete the content of a
                           					 work file when closing if the work file was referenced by a WRITE WORK FILEstatement that was never executed.) | |
| Default setting | ON | |
| Dynamic specification | yes | |
| Specification within session | no | 
Note:WFOPFA=OFF only affects main programs; for routines,
                     		  WFOPFA=ON always applies.