1 files changed, 2 insertions, 1 deletions

diff --git a/src/composite.c b/src/composite.c
index 518502be49f..5c56107fb77 100644
--- a/src/composite.c
+++ b/src/composite.c
@@ -1987,7 +1987,8 @@ preceding and/or following characters, this char-table contains
 a function to call to compose that character.
 
 The element at index C in the table, if non-nil, is a list of
-composition rules of this form: ([PATTERN PREV-CHARS FUNC] ...)
+composition rules of the form ([PATTERN PREV-CHARS FUNC] ...);
+they must be in the descending order of PREV-CHARS values.
 
 PATTERN is a regular expression which C and the surrounding
 characters must match.