HIDDEN RELEASABLE BARCODE OR QR CODE FOR INDICATING MATING OR NON-MATING OF TWO ELEMENTS, AND OPERATION THEREOF

A hidden releasable barcode or QR code for indicating mating or non-mating of two elements, which includes a conceiling feature which indicates the non-mating of said two elements, and an indicating feature which indicates the mating of said two elements. The conceiling feature and the indicating feature are one and the same structure with no relative motion between the conceiling feature and the indicating feature. The same structure on which the conceiling feature and the indicating feature are located is a rotatable platter, wherein the conceiling feature is an upper side of the rotatable platter, while the indicating feature is an underside of the rotatable platter having the barcode or QR code thereon. When the rotatable platter becomes unblocked, a spring (i.e., a torsion spring, coil spring, a combination thereof, or the like) or a mechanical linkage rotates the platter from the upper side of the platter (conceiling feature) to the underside of the platter containing thereon the barcode or the QR code (indicating feature).