"Well I would say the simpler and more direct a charter is the easier it is to get people to sign up to it."

I wasn't thinking of getting "guardians" to sign it (some hope! they're far too superior to do that!). Instead, I was thinking of publishing something unilaterally, plain simple common sense that most members of the public would see as reasonable. Guardians might not acknowledge it publicly but they'd be hesitant to breach it.