One was used for sea work. It was a grammatical code, which, although simple enough in its patent aspect, was not easy to memorise with that strict accuracy which is so essential to future use. Shortly, this code ran somewhat on the following lines, although English names are therein substituted in order to give better illustration. Needless to add, these messages were worded in the language of the country in which they were despatched, and signed with an assumed name which would be in common use in that country.
I. Communications signed with _Christian Name_ refer to _War Ships_.
Communications signed with _Surname_ refer to _Merchant Ships_.
II. _Please send a copy of_ "_The Times_" _to_ ... means "a base is being formed at ..."
III. I received a letter from ... _on_ ...
means { German auxiliary cruiser(s) in port at ... { German battleship(s) hanging about near ...
IV. I received a message from ... _on_ ...
means { German large merchant ship in port at ... { German cruiser hanging about near ...
means { German small merchant ship in port at ... { German torpedo-boat(s) hanging about near ...
VI. I am expecting a message from ... _on_ ...
means { German collier(s) in port at ... { German submarine(s) hanging about near ...
VII. The _first blank_ in the sentence is to be filled in with the _name of the place_ at which the base is being formed, or at which the ships have been seen.
VIII. The _second blank_ in the sentence, after the word "on" is to be filled in with a _day of the week_ indicating the number of ships seen (_see_ over, IX).
IX. 1 is Monday 2 is Tuesday 3 is Wednesday 4 is Thursday 5 is Friday 6 is Saturday 7 is Sunday 8 is Monday-week 9 is Tuesday-week, and so on. 15 is Monday-fortnight, and so on.
X. If, _instead of the singular person_ "I am (had)," the _plural_ "We are (had)" is written, it means that the ships in question, if merchantmen, have left port and are _going South_.
XI. If neither the first person singular nor plural is written and the communication begins, for instance, "Letter from ... _on_ ..." it means that the ships in question, if merchantmen, have left port and are _gone North_.
XII. Any mention of _illness_ means that the ships are _disabled_.
XIII. _I am expecting a letter from_ ... _on_ ... means that several German warships (or merchantmen) of different classes (or sizes) have been seen.