diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index cb2ddc3..b211dcb 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -2486,6 +2486,9 @@
 								*cpo-Z*
 		Z	When using "w!" while the 'readonly' option is set,
 			don't reset 'readonly'.
+								*cpo-z*
+		z	Special casing the "cw" and "d" command (see |cw| and
+			|d-special|).
 								*cpo-!*
 		!	When redoing a filter command, use the last used
 			external command, whatever it was.  Otherwise the last