I write many telegraphic reviews of monographs and textbooks.
Occasionally I see certain books do something I think should become
an industry standard, namely tagging nearly every theorem, lemma, definition,
example, exercise, etc. with some short mnemonic nickname, so readers need
not depend solely on a numbering scheme for cross-references, etc.
Examples of books that employ this laudable practice (and just happen to come to mind) include Epstein's Word Processing in Groups and Thurston's Three-Dimensional Geometry and Topology.
My question: what author and/or publisher initiated this practice?
(I'd like to cite the original source as a comparison when I feel the visual design of a book makes it difficult for browsing.)