TheCodeBreakers
in the main on four systems. American cryptanalysts ranked these on
four levels according to the inherent difficulty of their solution and the
messages that they generally carried. Intercepts were then solved in the
order of this priority schedule.
Simplest of all, and hence the lowest in rank and last to be read
(excluding plain language), was the LA code, so called from the indicator
group LA that preceded its codetexts. LA did little more than put kata
kana into roman letters for telegraphic transmission and to secure some
abbreviation for cable economy. Thus the kana for ki was replaced by the
code form CI, the kana for to by IF, the two-kana combination of ka + n by
CE. Its two-letter codewords, all of either vowel-consonant or consonant-
vowel form and including such as ZO for 4, were supplemented by a list
of four-letter codewords, such as TUVE for dollars, SISA for ryoji ("consul"),
and XYGY for Yokohama. A very typical LA message is serial 01250 from
annaabi.ee 
