The Wumen Guan has an appendix titled "Zen Caveats" (禪箴) with one-line aphorisms dealing with Zen practice The word "zhēn" (箴) means "caveat", "warning", or "admonition", but it also has the meaning of "needle" or "probe" (as in acupuncture needles) and is sometimes translated as "Zen Needles".