I wouldn't bother with the pet tags. I had to make a set quick 'cos my disks didn't get to my unit before we left the UK and to be honest they do the job okay, but if you are doing anything strenuous, the light engraving that they do will soon wear and it'll be hard to read the info.
Dog Tags Are you in the vetinary Corp, a yank or a Walt.
If you need a new set of identity discs because you've lost them speak to your friendly REME armourer/welder as alot of the time they make them up for the clerks and it saves you getting into trouble for the sake of a couple of beers.
none of the above..ex South African forces and ex British Army. now in the TA and I have only ever called them dog tags, as did everyone else I knew and worked with.
but yeah, I will jsut get a set made up somewhere rather than going through the clerks.