Add guidance if hash value changes are detected.

index.html

@@ -5570,9 +5570,18 @@ <h3>Base Context</h3>
 command from a modern Unix command interface line:
 `curl -s https://www.w3.org/ns/credentials/v2 | openssl dgst -sha384 -binary | openssl base64 -A`
         </p>
+        <p>
 More details regarding this hash encoding method can be found in the <a
 href="https://www.w3.org/TR/SRI/#integrity-metadata">integrity metadata</a>
 section of [[SRI]].
+        </p>
+        <p class="note" title="See errata if hash value changes are detected">
+It is extremely unlikely that the files that have associated cryptographic hash
+values in this specification will change. However, if critical errata are
+found in the specification and corrections are required to ensure
+ecosystem stability the cryptographic hash values might change. As such, the
+HTTP cache times for the files are not set to infinity and implementers are
+advised to check for errata if a cryptographic hash value change is detected.
         </p>
         <p>
 This section serves as a reminder of the importance of ensuring that, when