I can't believe it ! - where are you all? There's usually several posts before I get around to looking.
Sir Henry Hobhouse, Postmaster General at the start of WWI, after consulting with the Admiralty, issued an Instruction on 3 August 1914 to all head post offices on how to deal with naval mail. These instructions stated ".... stamps had to be cancelled with diagonal lines in ink or indelible pencil...."
Surprisingly good examples of the implementation of this instruction, such as the undated cover shown, are not common.
Specific instructions on the handling of naval registered mail was issued in a POC of 17 August 1914. The absence of a registration cancel front or back, on this cover is unusual. However the use of a blank / dumb registration label is significant
The boxed censor mark CENSORED / C.H.P. is known from the Cressy Class armoured cruiser HMS Crescent. The initials are those of Rev. C.H.Payton.
Cheers
Very nice Tony.. Something I've not seen before.
Chris