a.Identification required. Except as otherwise provided in this section, you, as a manufacturer, importer, or maker of a firearm, must legibly identify the firearm as follows:

1.SERIAL NUMBER, NAME, PLACE OF BUSINESS. By engraving, casting, stamping (impressing), or otherwise conspicuously placing or causing to be engraved, cast, stamped (impressed) or otherwise placed on the frame or receiver thereof, an individual serial number, in a manner not susceptible of being readily obliterated, altered, or removed. The serial number must not duplicate any serial number placed by you on any other firearm. The frame or receiver must also be marked with either: Your name (or recognized abbreviation), and city and State (or recognized abbreviation) where you as a manufacturer or importer maintain your place of business, or in the case of a maker, where you made the firearm; or if a manufacturer or importer, your name (or recognized abbreviation) and the serial number that begins with your abbreviated Federal firearms license number, which is the first three and last five digits, as a prefix to a unique identification number, followed by a hyphen, e.g., "12345678-[unique identification number]"; and

2.MODEL, CALIBER OR GAUGE, FOREIGN MANUFACTURER, COUNTRY OF MANUFACTURE. By engraving, casting, stamping (impressing), or otherwise conspicuously placing or causing to be engraved, cast, stamped (impressed) or placed on the frame or receiver, or barrel or pistol slide (if applicable) thereof certain additional information. This information must be placed in a manner not susceptible of being readily obliterated, altered, or removed. The additional information shall include:

i.The model, if such designation has been made;

ii.The caliber or gauge;

iii.When applicable, the name of the foreign manufacturer or maker; and

iv.In the case of an imported firearm, the name of the country in which it was manufactured. For additional requirements relating to imported firearms, see Customs regulations at 19 CFR part 134.