utf8.c: Add comment

diff --git a/utf8.c b/utf8.c
index b71ae48..a8c3832 100644 (file)
--- a/utf8.c
+++ b/utf8.c
@@ -1497,6 +1497,10 @@ Perl__to_fold_latin1(pTHX_ const U8 c, U8* p, STRLEN *lenp, const U8 flags)
 UV
 Perl__to_uni_fold_flags(pTHX_ UV c, U8* p, STRLEN *lenp, U8 flags)
 {
+
+    /* Not currently externally documented, and subject to change, <flags> is
+     * non-zero iff full folding is to be used */
+
     PERL_ARGS_ASSERT__TO_UNI_FOLD_FLAGS;
 
     if (c < 256) {