2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/137040We define Markoff words as certain factors appearing in bi-infinite words satisfying the Markoff condition. We prove that these words coincide with central words, yielding a new characterization of Christoffel words.4 pages, 2 figures, submitted to Information Processing LettersCombinatorics68R15text