diff --git a/data/key-namespaces.csv b/data/key-namespaces.csv
new file mode 100644
index 0000000..2abd23c
--- /dev/null
+++ b/data/key-namespaces.csv
@@ -0,0 +1,5 @@
+code,description,specification
+mdta,Reverse DNS naming convention,QT
+me4c,Metadata sample entry four-character-code,ISO
+udta,QuickTime user data,QT
+uiso,ISO user data,ISO
diff --git a/src/app/(rest)/registered-types/key-namespaces/page.mdx b/src/app/(rest)/registered-types/key-namespaces/page.mdx
new file mode 100644
index 0000000..4f3c8c2
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+++ b/src/app/(rest)/registered-types/key-namespaces/page.mdx
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+import { DataDisplay } from "@/components";
+
+export const metadata = {
+    title: "Key Namespaces"
+};
+
+# Key namespaces
+
+Multiplexed timed metadata tracks (`mebx`) in ISO/IEC 14496-12 use the `MetadataKeyDeclarationBox` (`keyd`) to declare the type and interpretation of metadata keys carried in each sample entry. The `key_namespace` field is a 4CC that identifies the domain and structure of the associated `key_value`.
+
+## Registered key namespaces
+
+<DataDisplay csv="key-namespaces" />