Weird, I think I just now realised the scale of ST6 ! I mean the numbers going are huge compared to most of the previous ones where there were 6 or 7 people, or a dozen going! We never really thought of them as 'rallies', but this one seems to qualify, somehow
and so we've got no 'rules' as such. You are right about the Tee-shirts, for example, its always done that way, just never occurred that it could be applied ST ...
Mind you, if (Crom forbid!) I somehow don't make it to ST6, I will rip up my Tee on principle!