Clarify how subscriptions share a connection

Author: ianswett

draft-ietf-moq-transport.md

@@ -550,15 +550,16 @@ property of the subscription and the original publisher's priority is a
 property of the Track and the Objects it contains. In both cases, a lower
 value indicates a higher priority, with 0 being the highest priority.
 
-The Subscriber Priority is considered first when selecting
-a subscription to send data on within a given session. When two or more tracks
+The Subscriber Priority is considered first when selecting a subscription
+to send data on within a given session. When two or more subscriptions
 have equal subscriber priority, the original publisher priority is considered
 next and can change within the track, so subscriptions are prioritized based
 on the highest priority data available to send. For example, if the subscription
 had data at priority 6 and priority 10 to send, the subscription priority would
 be 6. When both the subscriber and original publisher priorities for a
-subscription are equal, send order is implementation-dependent, but the
-expectation is that all subscriptions will be able to send some data.
+subscription are equal, how much data to send from each subscription is
+implementation-dependent, but the expectation is that all subscriptions will
+be able to send some data.
 
 The subscriber's priority can be changed via a SUBSCRIBE_UPDATE message.
 This updates the priority of all unsent data within the subscription,