I assume you are talking about CDNN, and their used Magazines. The "Law Enforcement" Magazines will all have the Restricted Markings from the 1994 - 2004 Federal Ban...
The "German" made Magazines are from J. P. Sauer & Sohn, and will have either a dovetail back, or "zipper" back where the Magazine is spotwelded together.
The "Italian" made Magazines are from Mec-Gar, and may be either "Ban Era" with the Restricted Markings, or "Post-Ban" without them.
There are US Made Magazines by Checkmate, which outwardly look similar to the Mec-Gar made units, that may be the used versions not marked as "Italian".
You can actually add +2 "Magazine Extensions" to the Mec-Gar or Checkmate magazines, but the German magazines, will be impeded by the lower "dimples".