We have recently moved to a platform that uses four character codes for accounts; the old system had two characters. As accounts are migrated over onto the new platform, the convention is to use “x2y2” so it’s clear that it has a predecessor on the old system.
Gloriously, account RD was moved across, so we now have “R2D2”.
Someone has now set up a new account “C3PO”on the system now, which is causing a few problems because of the “o”/ “zero” thing, and we don’t normally use “letter O”. But once something is set up it’s too much hassle to change it…. I chuckle every time I see it.