* src/regex.h (re_match_object): Improve commentary.

1 files changed, 6 insertions, 2 deletions

diff --git a/src/regex.h b/src/regex.h
index 817167a07ca..51f4424ce94 100644
--- a/src/regex.h
+++ b/src/regex.h
@@ -168,8 +168,12 @@ extern reg_syntax_t re_syntax_options;
 
 #ifdef emacs
 # include "lisp.h"
-/* In Emacs, this is the string or buffer in which we
-   are matching.  It is used for looking up syntax properties.  */
+/* In Emacs, this is the string or buffer in which we are matching.
+   It is used for looking up syntax properties.
+
+   If the value is a Lisp string object, we are matching text in that
+   string; if it's nil, we are matching text in the current buffer; if
+   it's t, we are matching text in a C string.  */
 extern Lisp_Object re_match_object;
 #endif