The term 'Cliff Notes' is a reference to the popular series of study guides created by CliffsNotes, Inc. The term is often used as a shorthand for any type of condensed summary of a text. The crossword solution for this term is 'YODEL, ' which is a form of singing that involves rapidly changing between the normal voice and falsetto. Yodeling is often associated with Alpine folk music and is used to communicate over long distances.