Update index.html

Co-authored-by: Michael B. Jones <[email protected]>

index.html

@@ -858,7 +858,7 @@ <h2 id="securing-vcs-with-cose">Securing JSON-LD
             <a data-cite="RFC9596#section-2">COSE "typ" (type) Header Parameter</a>,
             SHOULD be <code>application/vc+cose</code>.
             The <code>content type (3)</code> header parameter SHOULD be <code>application/vc</code>.
-            The <code>content type</code> header parameter is optional, and can be used
+            The <code>content type (3)</code> header parameter is optional, and can be used
             to express a more specific media type than <code>application/vc</code> when one is available.
             See <a data-cite="RFC9052#section-3.1">Common COSE Header Parameters</a>
             for additional details.