Card Identification Forum

Wondering if someone could help clarify a couple of questions for me.  While uploading card images for the two inserts in the subject line, I noticed the card numbers listed on the back of my cards doesn't match the listed checklist.  Looking at other images uploaded both to the site, as well as eBay, COMC, google, etc, I have noticed varying letter prefixes.  I have attached the scanned image of one of the cards, Field Force Insert #76.  The checklist, and other images list the cards as WFF-76, but mine is EFF-76.  In the Red Hot Rookes, listed as WRHR-53, mine is CRHR-53.  Can somebody help clarify this? 

The letter prefixes are based on divisional alignments. E= East, C=Central, W=West. The Red Hot Rookies should be listed with the C prefix since Lamar Thomas was drafted by the Bucs. They were in the NFC Central.

Thanks for the feedback.  That makes sense now that you explained it.  I have been racking my brain for days trying to figure this out.  Thanks again!