Deputy is a rank or title, or part of a title, use in various organizations with a codified command structure. It often designates someone who is "second-in-command," and as such, may precede the name of the rank directly above it. For example, a "Deputy Master" is likely to be second-in-command to the "Master" in an organization utilizing both such ranks. Dep. is the common abbrevation of "Deputy" and most widely accepted.