diff --git a/matroska_tags.xml b/matroska_tags.xml
index d18175b09..28cac57d1 100644
--- a/matroska_tags.xml
+++ b/matroska_tags.xml
@@ -337,6 +337,20 @@ the same tone as the musical piece (e.g., "441.34" in Hertz).
The value is a normalized absolute sample value of the target audio stored as a string without spaces (e.g., "1.0129").
Note that ReplayGain information can be found at all `TargetType` levels (track, album, etc).
+
+ EBU R 128 Loudness.
+ The value is the Loudness, K-weighted, relative to nominal full scale (LKFS) defined in [@!ITU-BS.1770] normalized to a Target Level of -23.0 LUFS as in [@!EBU-R.128].
+ This value is stored as a 32-bit floating-point number as defined in [@!IEEE.754] in little-endian order.
+
+
+ EBU R 128 True-peak level.
+ This corresponds to the "true-peak level", in units of dB True Peak (dbTP), defined in [@!EBU-R.128].
+ This value is stored as a 32-bit floating-point number as defined in [@!IEEE.754] in little-endian order.
+
+
+ Loudness Range, measures the variation of loudness on a macroscopic time-scale, in units of LU (Loudness Units) as defined in [@!EBU-TECH.3342].
+ This value is stored as a 32-bit floating-point number as defined in [@!IEEE.754] in little-endian order.
+
The International Standard Recording Code [@!ISRC],
diff --git a/rfc_backmatter_tags.md b/rfc_backmatter_tags.md
index 67a375f56..0408482eb 100644
--- a/rfc_backmatter_tags.md
+++ b/rfc_backmatter_tags.md
@@ -1,6 +1,22 @@
{backmatter}
+
+
+ LOUDNESS NORMALISATION AND PERMITTED MAXIMUM LEVEL OF AUDIO SIGNALS
+
+
+
+
+
+
+
+ LOUDNESS RANGE: A MEASURE TO SUPPLEMENT EBU R 128 LOUDNESS NORMALIZATION
+
+
+
+
+
GS1 General Specifications
@@ -20,6 +36,16 @@
+
+
+ IEEE Standard for Binary Floating-Point Arithmetic
+
+ IEEE
+
+
+
+
+
ID3 tag version 2.4.0 - Native Frames
@@ -69,6 +95,18 @@
+
+
+ Algorithms to measure audio programme loudness and true-peak audio level
+
+ ITU-T
+
+
+
+
+
+
+
Library Of Congress Control Number