diff --git a/extensions/classification.md b/extensions/classification.md
new file mode 100644
index 000000000..ada69a253
--- /dev/null
+++ b/extensions/classification.md
@@ -0,0 +1,48 @@
+# Information Classification
+
+As part of ISO27001 control objective A8.2 aims to address 'Information
+Classification' whereby information and data in an organization is properly
+managed, including classification in relation to sensitivity of the data,
+legislation etc. A.8.2.2 requires that electronic assets be 'labeled',
+and this extension allows the `data` of cloudevents to be appropriately labeled
+with the `classification` of the event being shared.
+
+Organizations will typically have their own internal Information Management
+policies and standards that might address these control objectives differently,
+however this extension provides a consistent framework for labeling
+events, where an organization can use their own internal values for
+`classification`.
+
+This extension is not opinionated on how this classification will be used and
+does not, for example, imply different encryption schemes etc.
+
+For Sainsburys-tech colleagues, additional information can be found on our
+internal confluence under `/display/IC/Information+Classification+Extension`,
+which, for example, includes the values from our own classification policies.
+
+## Attributes
+
+### classification
+
+- Type: `String`
+- Description: The `classification` of the `data`. The value SHOULD be expressed
+  in uppercase.
+- Constraints:
+  - REQUIRED
+  - MUST be a non-empty string (TBD)
+
+# Examples
+
+The following example shows a CloudEvent the producer has labeled as PUBLIC:
+
+```JSON
+{
+    "specversion" : "1.0",
+    "type" : "com.github.pull_request.opened",
+    "source" : "https://github.com/cloudevents/spec/pull/123",
+    "id" : "A234-1234-1234",
+    "datacontenttype" : "text/xml",
+    "classification" : "PUBLIC",
+    "data" : "<much wow=\"xml\"/>",
+}
+```