3. Definitions Section 921(a) of title 18, United States Code, is amended by adding at the end the following: (38) The term facilitator means any person engaged in the business of hosting a commercial marketplace in which offers for firearm sales, purchases, or other transfers are allowed to be made, except that such a person shall not be considered to be a facilitator with respect to any transaction that is made through the use of a website or mobile application owned or operated by the person if the transaction violates the terms of service of the website or mobile application and the person has made a good faith effort to enforce the terms of service by, at a minimum, auditing firearms transactions on a quarterly basis to ensure compliance with this chapter. (39) The term occasional means, with respect to transactions, fewer than 5 transactions in a 12-month period. (40) The term personal collection includes any firearm obtained only for the personal use of an individual and not for the purpose of selling or trading, except that a firearm obtained through inheritance shall not be considered part of a personal collection until the firearm has been possessed for 1 year. (41) The term business inventory firearm means, with respect to a person, a firearm required by law to be recorded in the acquisition and disposition logs of any firearms business of the person. (42) (A) The term frame means the part of a handgun, or variants thereof, that provides housing or a structure for the primary energized component designed to hold back the hammer, striker, bolt, or similar component prior to initiation of the firing sequence (such as a sear or the equivalent), even if pins or other attachments are required to connect such component to the housing or structure. (B) The term receiver means the part of a rifle, shotgun, or projectile weapon other than a handgun, or variants thereof, that provides housing or a structure for the primary component designed to block or seal the breech prior to initiation of the firing sequence