Oh god the memory!
I remember the day a third party company were engaged to audit the datacentre where are servers were. They were mainly HP DL variants and the serial number was on a sticker on the side of the chassis. So these guys were undoing the knurled locking nuts, sliding the server carefully out of the rack until they could read the sticker and log it and then sliding it back again.
All was going well until they found a rack with lots of 'servers' in it that had no sticker on the side. That rack was an HP EVA SAN and they were sliding out the disk trays. The EVA did not respond well.