Say you are the organizer of the BFS rally(TM), and you have all of the safety and inspection requirements that you propose should be required of all rally's, and some guy and his girlfriend arrive in a "worn out, but probably fine" 32' something or other but certainly doesn't meet all the ISAF requirements.
So you tell the guy that he can't join your rally because he doesn't have the experience and his boat doesn't meet specs. He says that's too bad because he was looking forward to having the weather routing info and really liked the t-shirt design you had made rally participants. But, says he, joining the rally is independent of him sailing to the islands, so he's leaving in the morning and he'll buy you a beer on the other side.
What do you do? The way I see it, your choice basically boils down to a couple of options.
1. Reinforce that he should not make this journey. Tell him that since you don't approve and he's not part of the rally, that he won't be getting your weather information, won't be getting your en-route broadcast channels of weather and recommenced route updates and most importantly, no t-shirt.
2. Tell him that you don't think he should make the journey, but if he's going anyway, share with him your weather info, let him know how you will communicate updates, and since he seems like a swell guy and clearly has a keen eye for graphic design, throw in the t-shirt as well.
I don't see how anyone would consider option one as the most safe option, if the guy is going to go anyway. If something happened to him out there, and you had information that would maybe have helped him, and withheld it leading to some sort of loss, you would probably feel pretty crappy about that.
If you go with option two, or some variation thereof, then congratulations the BFS Rally (TM) now has the same (de facto) requirements as the SDR.
Option 1. No doubt.
Just the thought of not having a BFS Tee would make his girlfriend pressure him into attending a SAS seminar and upgrade the boat. Hell - she'd take the boat away from him and do it herself.