From a reader…
I’ve been to Mass (Novus Ordo) in my college chapel where the priest did not wear the chasuble, but just an alb and a stole. Is that permissible? Are there guidelines for the priest on how to properly vest for Mass and which vestments he can and cannot use? I’ve seen cases were the priest does not even wear the cincture around his waste. And of course, the priest not wearing the amice (and very rarely, the maniple in the N.O.).
The rubrics are clear. A chasuble is required for the celebration of Mass. A cincture can be omitted if the alb is constructed in such a way that it is not needed (such as an alb with a sewn-in belt – I hate those), and the amice can be omitted if the alb clearly covers the priest’s street clothes entirely (I hate those). That means that the shirt collar should NOT be visible.
If (when), however, Father is offering Mass in a prison camp, as priests may be doing in the near future, he must make do with what he has.
If the parish he is at is so poor it cannot afford a chasuble, perhaps a gift from a wealthier parish can be arranged.
Meanwhile, Father should be urged not to go out half naked to say Mass. It’s embarrassing for everyone.