Header sequence: Version number, Date of last update MMDD, character field 'PLATFORM' followed by character field 'UNIQUE ID', and later character field 'OBJTYPE'
Signature developed utilising collection of frx files obtained from Fox Pro and Visual Fox Pro Databases, and from details of internal structure of file available at:
http://www.mattslay.com/pages/FoxPro-Report-FRX-Structure.html