Well alright, helping out with clan affairs is a great thing to do,but if you want to be in a clan, then, with very few exceptions, wear the tartan and there you go. If your surname is "MacKarrot", or whatever, then that helps no end(in yours and other's minds perhaps) with wearing that particular tartan, if it really matters and of course it does to some. As a sept member of a clan, well, maybe it matters to some too, but in reallity there are no entrance exams, initiation rites, or whatever to join most(all?) clans. Of course the parting of a sum of money does, as always, "oil the wheels" and perhaps adds to the sense of belonging.