True, it does denote clerical status, and yes, it’s not something one can arrogate to oneself. But as to the last point about being specifically allowed, I think that conveys more of a formal process than is really necessary, as by this point it’s basically a matter of local custom. Take Rome, for instance, where it seems rather common for altar boys and choir members to wear the collar. It’s not as if every single one of them has sent a letter to Cdl. Ruini requesting the use of the collar during liturgical functions. Rather, it is the approved custom of the locality that they are able to do so. Customs require a certain amoung of toleration or approval to get rolling, but once that occurs it doesn’t require further *specific *permission for individuals or parishes to observe the practice.