References for cancellations on battleship documentary revenues:

F = "A Catalog of Railroad Company, Street Railway Company, & Express Company Printed Cancellations on the 1898 U.S. Revenues," Richard D. Fullerton, ed., R.D.Fullerton, 34 South Quentin Ave, Dayton 3, OH, undated. ["Subtypes" classified by Fullerton such as a 0.25mm vertical shift in a period, for example, are not included in the table.]

T = "Railroad Cancellations on United States Revenue Stamps of the 1898 Issue," H. Tolman II, 1995

L = Cancellations contributed by John Langlois from 1898revenues.blogspot.com

M = Cancellations contained in R. Mustacich collection that are not included in the Fullerton and Tolman references