Clay, are you aware that verbage like that exists in EVERY single park in the entire USA ? In some form or fashion. Yup, even in parks that have never had an issue before. And even parks where people have "gotten permission" (as if that were needed). So that tells me that ........ while it *could* be applied, yet it doesn't *necessarily* apply. It all depends on mood, image, whim, luck , etc..... But I do not consider it to mean "no detecting", lest we all give up every beach, park, school, forest, etc......
I wonder why we never heard back from the relic-revivor on this ?? Are you still there relic-revivor ? Did you fight the ticket ? If you need the past incident of "dismissed" in that city (when this had happened before to someone), let me know, and I can maybe find the date and copy of that for you. That plus your having called in ahead, will most certainly get this one dismissed too.
Actually Tom the San Francisco Parks and Ports Code are the only regulations with that copyrighted wording. You won't find it anywhere else.
My point agrees with yours though I think. If the man doesn't want you poking around in a park or public place he has enough to cite you. I imagine that's true in most places except the federally managed public lands open to entry, permitted private land and locally designated public detecting areas.
You say you could fight that ticket and and have it "dismissed" (but not won?) but you haven't provided any information here how that would be done. Care to share with your fellow detectorists how to get a ticket in San Francisco dismissed? I'm sure there are at least a few of us here who would find that information useful.