Don't place a sticker or any other material on top of the processor Integrated Heat Spreader (IHS). Only Thermal Interface Material (TIM) should be applied between the processor IHS and the fan-heatsink. Using any other material will degrade the thermal transfer between the processor, the IHS, and the fan-heatsink. This could potentially damage the processor and void your warranty. See below for an example of what not to do.

The best way to identify and track a processor sold through your place of business is by documenting the serial number (ATPO) and the batch number (FPO) on the invoice, they are also listed on the shipping box.

An example is pictured below that illustrates where this can be found on an Intel® Core™ i7-8700. For more information on how to locate these two numbers, visit Where Can I Find Intel® Boxed Processors and Fan Part Numbers?