mnemonic

1. Something used to assist the memory, as an easily remembered acronym or verse.
2. An abbreviated word that resembles the full word, used so as to be easily recognized; as, the CIDE uses ... tags as mnemnonics for an italicised word or field.

In basic organic chemistry class, one may learn the mnenomic “Oh my, such good apple pie” to help remember the names of the dicarboxylic acids in increasing order of length, namely: oxalic, malonic, succinic, glutaric, adipic, and pimelic acids. (From L. Fieser's Organic Chemistry text).