[oneofthemguys]

Being that it's a state law, not a local law, any card issued by a doctor authorized by the state of California should be valid.

San Diego and, I believe, Riverside county tried to contest SB420/Prop 215 recently and the California Supreme Court told them too bad, thankfully.

I believe the county standardized card is to make law enforcement officials' lives easier. They don't know EVERY doctor that's allowed to give out cards, so ya see the trickery? San Diego county is rather populated, after all.