A correspondent writes:
"Can you point me to a good reference for why women are no longer required to wear a head covering during Mass?"
Throughout history it has been common for women to wear head coverings. This is something that has precedent in St. Paul’s epistles (see 1 Cor. 11:2-16).
It was mandated in the 1917 Code of Canon Law. Canon 1262 states:
1. It is desirable that, consistent with ancient discipline, women be separated from men...