About multi-criteria relationships
Number field, auto-enter serial number; one of the match fields to the Catering Line Items table In the Edit Relationship dialog box, the Allow creation of records in this table via this relationship option is enabled for the Catering Line Items table. This means that you can enter rental information in an empty portal row, and FileMaker Pro creates a related record for that rental.Finally, a portal is added to the Catering Line Items table on the Customers layout.