search.c (search_buffer): Improve a comment.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/search.c b/src/search.c
index c6c3062e649..fb76880b612 100644
--- a/src/search.c
+++ b/src/search.c
@@ -1314,7 +1314,9 @@ search_buffer (Lisp_Object string, ptrdiff_t pos, ptrdiff_t pos_byte,
              represented by the byte array of 256 elements.  For that,
              all non-ASCII case-equivalents of all case-sensitive
              characters in STRING must belong to the same character
-             group (every 64 characters form a group; U+0000..U+003F,
+             group (two characters belong to the same group iff their
+             multibyte forms are the same except for the last byte;
+             i.e. every 64 characters form a group; U+0000..U+003F,
              U+0040..U+007F, U+0080..U+00BF, ...).  */
 
           while (--len >= 0)