-
On PBP you have to follow a particular route, so a "secret" control is just one along the way that is unadvertised, where you have to get a stamp. They also have food etc, obvs
graunch-
I think there may be secret controls on WCW too.
The point of them is that you don't know where on the route they will be, so you have to follow the entire route in case you miss them (in which case your ride won't be validated). They're sort of coming back in the UK as a way of keeping routes close to their nominal distances (so you don't get a 600 that is actually 640km on the road, or without cluttering the ride with lots of info controls) using the 'mandatory route' option that are now in the rules and regs.
In the UK a secret control can just be someone in a lay-by at the side of the road. So you can't expect food or shelter.
The secret control(s) on PBP are slightly different, they usually do have food, beds, shelter, etc. Unless you're at the pointy end of the race they're also not very secret after the first few people get there and tweet about them.
Greenbank
Still not sure if I want to do PBP but entered Windsor Chester Windsor .. wtf is a secret control?