I can confirm what has been stated about serial numbers already.
MAH, PAH, PAP followed by 16 digits=CMC
+ and - in the middle=Prodisc
Also, don't be surprised that those CMC made discs can be of better quality. I've gone through two recent batches of Verbatim 8x discs (one DVD+R, the other DVD-R) that were made by Prodisc and both were horrible. 10 out of 25 DVD-R discs ending up as coasters for example, is NOT good. Whereas the 8x DVD-R ones I recently got hold of made by CMC have excellent scans.