The high-capacity magazine ban that came into effect in the United States via the enactment of the Federal Assault Weapons Ban led to the immediate cessation of HK offering American civilians access to new magazines that could hold more than 10 rounds. Because the assault weapons ban went into effect in September 1994, HK decided to promptly make a clear distinction between what magazines were designated for civilian sales and what magazines were not after September 1994; HK did this with addition of new magazine markings that stated “Restricted Law Enforcement / Government Use Only 10-94” for any magazine that held more than 10 rounds.
As a result of the addition of this company practice, consumers will find Restricted Law Enforcement / Government Use Only 10-94 stamped on magazines for a wide array of HK weapon types ranging from pistols to submachine guns. This marking is even on magazines made for weapons platforms that couldn't be accessed by the average civilian during the ban era, such as the HK UMP. Additionally, a very expensive secondary market for magazines that were made before September 1994, which have been designated as "pre-ban" magazines, quickly emerged during the ban era as firearms enthusiasts explored all possible legal ways around the 10 round restrictions placed upon their favorite weapons' magazines.
Ultimately, the federal restriction on the sale high-capacity magazines ended in September 2004 per a sunset provision included in the assault weapons ban legislation. While some states have enacted their own laws creating similar magazine capacity restrictions since 2004, the majority of states currently allow for the sale of new magazines holding more than 10 rounds. In most states, the impact of the ban era mostly remains visible through various firearms artifacts, such as HK's now defunct Restricted Law Enforcement / Government Use Only 10-94 marking.
Today, HK no longer adds such markings to their magazines. However, while these markings might not be tied to active federal laws, they act as a helpful reminder of the negative impact that misguided political efforts can have on American firearms enthusiasts.
Examples of parts with the Restricted Law Enforcement / Government Use Only 10-94 marking can be seen with the following links:
HK MP5 MP5K Magazine - 9mm - 30 Round - LEO Restricted Marked
HK UMP 30 Round Magazine - .40 S&W - LEO Restricted Marked