For whatever reason, pro wrestling also popped into my mind very early on. But then later I started thinking may high school football.
Looking at the letters, the K and the W look largest. On twitter, there is someone with the user name of these same four letters, in the same order. In their user name, the K and the W are in caps and the middle two letters are not. The letters are a play on the person's own name, if you compare the name to the letters. I googled the person's name and got their facebook account (Czech; the person and all their friends seem to be in that country). For privacy reasons and WS policy, I am not suggesting we all flock there, but I will say that I already looked over the person's (public) list of friends and none bore any resemblance to the UID. The twitter account was basically opened but never really used.
I had not thought specifically of the toe tag thing, but it is looking pretty logical at this moment. I do think the simplest explanation for the letters is that they are his initials. I looked at "van W*" names, mostly Dutch. And thought about K first names. I even saw a former football player who fit the initials K vW who was 6'6" and the right age, but it's not him. Maybe his reason for putting the "ca" in lower case was simply to differentiate it from the letters above.
Unfortunately I don't know of a good way to do a web search for a person using that kind of wildcard - like K* van W* or K* O* van W*. On the off chance that he was listed in a phone directory, looking over the names the old fashioned way would be easier than online, in this case.
But there is a good chance he is not in a local phone directory anyway, so it might be more useful to do a broader search if that were possible.
