Cal. Penal Code § 27531

The following terms have the following meanings for purposes of this article: (a) “Microstamp” means a microscopic array of characters that may be used to identify the specific serial number of a firearm from spent cartridge casings discharged by that firearm. (b) “Microstamping component” means a firing pin or other component part of a semiautomatic pistol that, when installed, produces a microstamp on at least one location of the expended cartridge case each time the pistol is fired. (c) “Microstamping-enabled” means either of the following: (1) The firearm’s manufacturer has certified in writing that the firearm contains a microstamping component that meets the performance standards established by the Department of Justice pursuant to subdivision (b) of Section 27532. (2) A licensed firearms dealer or gunsmith has certified in writing that they serviced the firearm to install a microstamping component that meets the performance standards established by the Department of Justice pursuant to subdivision (b) of Section 27532. (d) “Producing microstamping components” may include, but is not limited to, the process of engraving a firing pin to modify the pin into a microstamping component. (e) “Semiautomatic pistol” means a pistol, as defined in Section 16530, that has an operating mode that uses the energy of the explosive in a fixed cartridge to extract a fired cartridge and chamber a fresh cartridge with each single pull or activation of the trigger.