diff --git a/libavformat/rtp.c b/libavformat/rtp.c
index 5f45afb0cbba2e80c664ba260fe2096e3d1e4af3..adb7cc84015076f4126c18aae79a4cb733ea1683 100644
--- a/libavformat/rtp.c
+++ b/libavformat/rtp.c
@@ -29,6 +29,11 @@
 //#define DEBUG
 
 /* from http://www.iana.org/assignments/rtp-parameters last updated 05 January 2005 */
+/* payload types >= 96 are dynamic;
+ * payload types between 72 and 76 are reserved for RTCP conflict avoidance;
+ * all the other payload types not present in the table are unassigned or
+ * reserved
+ */
 static const struct
 {
     int pt;