The ASSOC keyword is a field qualifier to specify that the field is to be treated as part of a named association.
field.name ASSOC "name"
The ASSOC keyword causes field.name to be treated as part of the named association.
LIST ORDERS PART.NO QTY EVAL "SELL * QTY" ASSOC LINE.ITEMS
This command processes records from the ORDERS file and reports the multivalued part numbers, quantities and calculated line total value for each record. The evaluated expression is treated as a member of the association LINE.ITEMS to which the other reported fields already belong.