Shirt, Mail / Byrnie
A mail byrnie was a corselet or vest of mail, covering the torso, abdomen, shoulders, and sometimes a small part of the upper arms. Mail Byrnies in antiquity often featured a second layer protecting the shoulders in the form of a mail collar or shoulder piece. Mail isn’t really effective without some kind of padding worn underneath so it’s assumed that mail here will be worn with a light coat armor or aketon. For more information see the entry on Mail in the Armor Glossary, and also see Mail Habergeon and Mail Hauberk).