The Major System
The major system allows you to convert numbers into sounds and thus words, thereby making them memorable. Each number keys to a certain kind of consonant, and vowels and some other sounds are unassigned. 1 is T or D. 2 is N.
The Major System is based not around letters but sounds, so “enough” and “knife” would both code for 28. “Knife” would probably be easier to remember visually though. No matter what letter you choose, each number corresponds to essentially the same position for your mouth.
Diplomatic Services operational officer
FROM THE BOOK