Some of this really is common sense. Like I say - Everyone links items to a serial number in some way, and most things have a serial number, though admittedly some items only have a batch number, but that is typically small components.
Ninja just added to the list. My initial post was short and should have included some of this stuff, so I appreciate people adding on.In this case I hadn't thought of how many companies have, for example, asset number plates or stickers or whatever, but we come back to those each have to be linked to a serial number (in most cases for anything of value) and quite often a purchase order as well. A bottle of milk may not have a serial number, but it has a batch number printed on it somewhere.