The field REDUCTION (upper case) now exists in both section access and section application (all field values are also upper case). The two fields would normally be totally different and separated, but if the Initial Data Reduction Based on Section Access option has been selected, they will link and reduce the number of records displayed to the user.
The field OMIT in section access defines the fields that should be hidden from the user.
The result will be as follows:
User A can see all fields, but only those records connected to REDUCTION=1.
User B can see all fields except NUM, and only those records connected to REDUCTION=2.
User C can see all fields except ALPHA, and only those records connected to REDUCTION=3.