Coding mnemonic
Coding mnemonics are used for encoding numbers. Because words are much easier for most of us to remember, a system that transforms numbers into letters is one of the best ways for remembering numbers — as seen in the modern innovation of encoding phone numbers into letters (0800-ANSETT).
A coding system is very useful for remembering numbers, but it must be said that few people have sufficient need to memorize long numbers to make the initial cost of learning the code acceptable.