Junior Deacon (JD)
The jewel of his office is the Square & Compass with the Moon in the center (rather than a sun, as with the Senior Deacon), which signifies that he is in the West. The Junior Deacon of a Masonic Lodge is an assistant officer of the Lodge. He sits to the lower right of the Senior Warden.
The Junior Deacon’s principle roles are to assist the Senior Warden by carrying messages from the Senior Warden in the West to the Junior Warden in the South and to guard the inner door of the Lodge.
It is also his duty to ensure that the Tyler (also spelled "Tiler") is guarding the door and only allowing visitors to enter after they have been properly vouched for. The Junior Deacon and the Tyler communicate with each other by knocking on the door … the Tyler from the outside, the Junior Deacon from the inside.
The Junior Warden’s position is similar to an Assistant Manager.