The first step is tagging the field we want to save. Just as with intra-frame data, inter-frame data uses a special RETRIEVE method to identify the field to be saved, along with an inter-frame data name. The StorePersistentField method stores the value in the field to the FRM file. Here's our sample request field:
FIELD request (Fixed 1) RETRIEVE (StorePersistentField request) (Table request_codes) "Request"