search.c (search_buffer): Improve a comment.

diff --git a/src/search.c b/src/search.c
index c6c3062e64989741717e070e58c3316d5c4bb3e8..fb76880b612449057675678ba86905180d597209 100644 (file)
--- 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)