Who knew graffiti had rules? Well, really it isn't graffiti, I guess, if you follow the rules. We've shown pictures of the 'art' on this concrete below Castle Hill before. (The ruins of a failed condo project from years ago.) But the other day we noticed this sign. So this area will be a battleground between those with permission and those without. I shot a few pictures a few weeks ago and will give you a couple of examples in the coming days.