Merge pull request #3281 from w3c/Issue1814-timing-adjustable

Issue 1814 on timing adjustable

understanding/20/timing-adjustable.html

@@ -49,6 +49,8 @@ <h2>Intent of Timing Adjustable</h2>
 
       <p>In some cases, however, it is not possible to change the time limit (for example, for an auction or other real-time event) and exceptions are therefore provided for those cases.</p>
 
+      <p>Content that operates on a timer does not need to be time adjustable if there is an alternative that does not rely on a timer. For example, a web application such as an email client provides notification of new email arriving with a temporary message (such as a 'toast' message) in the lower right-hand side of the interface, and the message disappears after 5 seconds. Users are able to identify the arrival of email through other means, such as viewing the Inbox, so the disappearance of the message does not set a time limit on the their ability to determine if new mail has arrived. If the user has no other means of discovering the same information (or performing the same function), then each message would need to meet this Success Criterion in order to provide users with sufficient time to access the information.</p>
+
       <p>
 
          <strong>Notes regarding server time limits</strong>