A collection of chasidic discourses delivered by the Rebbe in 5732 / 1972-73. Most of the maamorim in the book have never been published before. They were transcribed from tape, video or from the listeners notes.
Mnemonics have always been used in Judaism as a tool to remember numbers and laws. The proof is found in the Haggadah for Passover when Rabbi Yehudah gave a mnemonic to remember the order of the ten plagues.