Abstract: Disclosed is a rack fastener to engage and retain a first member and hold a second member to the first member. The fastener has two coextensive studs, each having base portions, to install from a back surface of the first member each into separate apertures thereof, such that the studs extend through the separate apertures from a front surface of the first member. A connecting portion connects the two base portions. There is also, a clipping portion extending, directly or indirectly, from one of the base portions, the clipping portion having at least one engagement face to engage a region of another aperture of the first member so that the fastener is substantially prevented from being separated from the first member. The two studs can pass through respective apertures of the second member, and thereafter fasteners can engage each stud to secure the second member to the first member.

Abstract: A method of monitoring product identification at a transaction terminal by sending either visible light signals, near infra-red light signals or wireless signals to a recording device that records video footage of a transaction terminal in conjunction received product identification information. A system for effecting the method along with light based and wireless transmitting units are disclosed.