Type F encompasses all cancels that are not issued to the ship through regular postal channels, or cancels which may have been issued by the Post Office but which are not classifiable under the present system.
The following cancel is classified as Type F
The following cancel is classified as Type F
The following cancel is also classified as Type F even though it
resembles a standard type
Locy System for Classifying Naval Postmarks, As Revised ©, of the Universal Ship Cancellation Society is excerpted and reprinted with permission.