diff --git a/codec_iana.md b/codec_iana.md
index 41fd843c7..5896460c5 100644
--- a/codec_iana.md
+++ b/codec_iana.md
@@ -57,6 +57,7 @@ A_AAC/MPEG4/SSR | 2 | Scalable Sampling Rate | This document, (#a-aac-mpeg4-ssr)
 A_AC3 | 2 | Dolby Digital / AC-3 | This document, (#a-ac3)
 A_AC3/BSID9 | 2 | Dolby Digital / AC-3 | This document, (#a-ac3-bsid9)
 A_AC3/BSID10 | 2 | Dolby Digital / AC-3 | This document, (#a-ac3-bsid10)
+A_AC4 | 2 | Digital Audio Compression AC-4 | This document, (#a-ac4)
 A_ALAC | 2 | ALAC (Apple Lossless Audio Codec) | This document, (#a-alac)
 A_ATRAC/AT1 | 2 | Sony ATRAC1 Codec | This document, (#a-atrac-at1)
 A_DTS | 2 | Digital Theatre System | This document, (#a-dts)
diff --git a/codec_specs.md b/codec_specs.md
index e379bb634..10833dffa 100644
--- a/codec_specs.md
+++ b/codec_specs.md
@@ -613,6 +613,14 @@ Using this Codec ID is **NOT RECOMMENDED** as many Matroska Players don't suppor
 
 Initialization: none
 
+### A_AC4
+
+Codec ID: A_AC4
+
+Codec Name: Digital Audio Compression AC-4
+
+Description: Each Matroska frame corresponds to a "Raw AC-4 frame" as defined in Section 4.2 of [@!ETSI-TS103-190-1].
+
 ### A_ALAC
 
 Codec ID: A_ALAC
diff --git a/rfc_backmatter_codec.md b/rfc_backmatter_codec.md
index 163808ff9..4d483881c 100644
--- a/rfc_backmatter_codec.md
+++ b/rfc_backmatter_codec.md
@@ -91,6 +91,16 @@
   </front>
 </reference>
 
+<reference anchor="ETSI-TS103-190-1" target="https://www.etsi.org/deliver/etsi_ts/103100_103199/10319001/01.03.01_60/ts_10319001v010301p.pdf">
+  <front>
+    <title>Digital Audio Compression (AC-4) Standard; Part 1: Channel based coding</title>
+    <author>
+      <organization>European Telecommunications Standards Institute</organization>
+    </author>
+    <date month="February" year="2018" />
+  </front>
+</reference>
+
 <reference anchor="IEEE.1857-3" target="https://standards.ieee.org/ieee/1857.3/10645/">
   <front>
     <title>IEEE Standard for a System of Advanced Audio and Video Coding</title>