Clarify that equivalent algorithms for validation are allowed.

Author: msporny

index.html

@@ -1951,8 +1951,8 @@ <h3>Processing Model</h3>
           </li>
           <li>
 If the document is a JSON-LD document, the software uses the algorithm provided
-in Section [[[#context-validation]]] to validate all JSON-LD Context values used
-in the document.
+in Section [[[#context-validation]]], or one providing equivalent protections,
+to validate all JSON-LD Context values used in the document.
           </li>
         </ol>