include 'resulting from queue selector attachments'

Author: adamtuck-msft

articles/communication-services/concepts/router/classification-concepts.md

@@ -26,7 +26,7 @@ The process of classifying a Job involves optionally setting the following prope
 
 ## Fallback queue
 
-The fallback queue is used when queue selectors are unable to select a queue and the job does not have a `queueId`. In this case, if the fallback queue is defined, the job is assigned to it.
+The fallback queue is used when queue selectors, resulting from queue selector attachments, are unable to select a queue _and_ the job does not have a `queueId`. In this case, if the fallback queue is defined, the job is assigned to it.
 
 ## Prioritization rule