title: Azure Event Subscription - Filters Case Sensitive or Not Case Sensitive
body: <p>It appears that Azure Event Subscription Filters  are not case sensitive. Currently I have got a filter created:
  <a href="https://i.stack.imgur.com/GMNQg.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GMNQg.png" alt="enter image description here" /></a></p>
  <p>However in the Valid keys says all lower case, however the filter works &quot;eventType&quot; also the documentation indicates. In this link: <a href="https://docs.microsoft.com/en-us/azure/event-grid/event-filtering" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/azure/event-grid/event-filtering</a>
  For events in the Event Grid schema, use the following values for the key: ID, Topic, Subject, EventType, DataVersion, or event data (like data.key1).</p>
  <p>Currently it works, however, there are few in the team wanting to find out what is the recommended approach. Does anyone know the preferred way, or is this a documentation error.</p>