None that I remember seeing in the past, but I don't think I've ever had a good look for them. I wouldn't be at all surprised if they're painted over and invisible, but I'll have a good thorough look tomorrow out in the sunshine and see what turns up.

I've been poking around a bit on bmxmuseum.com. Eyeballing, it looks very much like it might be a 1997 Haro Zippo, though this one thread reckons the 1997 Haro Revo (which I haven't been able to find any other information about anywhere) is more or less the same: http://bmxmuseum.com/forums/viewtopic.php?id=20515

(If this is a 1997 model Haro, the previous owner needs to be smacked for bringing it to such a state in only 2-3 years!)