Before the stark fist of HTTP and HTML crushed all who opposed it, there was a protocol called RIP, which used [0-9A-Z] for its numbering. RIP allowed sysops to put up vector graphics, and create windowing systems and other things for their bbses. They called them meganums. The idea caught on for a brief time, and then the internet rolled over it like a tank.
If you've a morbid curiosity, http://thebbs.com has a bunch of info on them (Look for RIP screens, utilites, etc.)
Its death was not a bad thing, since RIP was brutish and ugly...