diff --git a/index.bs b/index.bs
index 8d9e2b3..c830bd9 100644
--- a/index.bs
+++ b/index.bs
@@ -195,15 +195,15 @@ spec: mimesniff; urlPrefix: https://mimesniff.spec.whatwg.org/#
A {{MediaDecodingConfiguration}} has three types:
- file is used to
- represent a configuration that is meant to be used for plain file
- playback.
+ represent a configuration that is meant to be used for playback of
+ media sources other than {{MediaSource/MediaSource}} as defined in
+ [[media-source]] and {{RTCPeerConnection}} as defined in [[webrtc]].
- media-source is used
to represent a configuration that is meant to be used for playback of
- a {{MediaSource/MediaSource}} as defined in the [[media-source]]
- specification.
+ a {{MediaSource/MediaSource}}.
- webrtc is used to
represent a configuration that is meant to be received using
- {{RTCPeerConnection}} as defined in [[webrtc]]).
+ {{RTCPeerConnection}}.