The Abbey symbol is a war hammer. Heraldically it is a black hammer displayed bendwise dexter on a red roundel. All members are entitled to use this symbol. The hammer displayed bendwise sinister is the particular symbol of the Abbey retainers and used only by them.
Additionally Abbey members may be entitled to wear a hammer pendant. Brothers and Sisters who have demonstrated their abilities with heavy weapons may wear a brass hammer. Retainers who have done the same may wear a steel hammer. The hammer of the Fidei Defensor has a brass shaft with a steel head. Copper hammers are worn by non-fighters who have contributed well to the household. Novices wear a roundel with a hammer cut-out. Occasionally in the past, special hammers have been given out for extraordinary reasons to Abbey friends and allies.
The Abbey admits new members with the consensus of the current membership. Candidates who request membership in the household undergo a six-month stint as a novice, to allow the novice to learn about the members and vice versa. After the six months a formal vote is taken, and an accepted novice chooses whether to be a brother or sister, or a retainer. No Abbey member may be the member of another household concurrently.
Another fun ceremony in the Abbey is for the retiring of old gear (such as war shields and old fighters). Here's a pic from one such ceremony. Don't happen to have any of retiring a fighter...
A typical Abbey procession is led by a retainer, followed by members of the Caput Mortuum, followed by the Fidei Defensor, They are followed by the Abbot attended by the Prior Vice-Garant. Next comes the remaining members of the Caput Mortuum. Behind comes the incense burner, leading the other Abbey brethren. The entire procession is wreathed in a cloud of retainers, properly armed and wearing their red capes.