TheCodeBreakers
Nothing was said about oil. On November 26, the day that he handed it
to Nomura, Tokyo circularized its major embassies with an open code.
While the winds code envisioned abolition of all communication with the
embassies, this new code—called the INGO DENPO ("hidden word") code —
was intended for a less critical situation. It seems to have been arranged
at the request of the consul in Singapore in case code but not plain
language telegrams were prohibited. It set up such equivalences as
ARIMURA = code communications prohibited; HATTORI = relations between
Japan and (name of country) are not in accordance with expectation;3
KODAMA = Japan; KUBOTA = U.S.S.R.; MINAMI =U.S.A.; and so on. "In order
to distinguish these cables from others," Tokyo said, "the English word
STOP will be added at the end as an indicator. (The Japanese word OWARI
[end] will not be used.)"
The next day, November 28, the Navy cracked the transposition for
annaabi.ee 
