If it is not on the internet, it doesn't exist  

Seriously, though, being web-based is not a measure of non-notability.  What's needed is a measure of how broadly something is used (on the web or not).  If the symbol is just identified by a single person enterprise on a series of closely-related websites (which may be the case) it isn't notable.  If a number of independent groups use it, it's a different story.  Basically, can someone come up with at least two usages that is not a) A website maintained by Per Bylund or b) a wikipedia mirror?