WD13, Line 550 says:
The client subscriptions which it has acknowledged.
This implies a session could contain subscriptions from multiple clients. Also, based on how subscriptions are defined elsewhere, we shouldn't include the 'acknowledged' conditional.
The client's subscriptions.
Line 1337 says:
A subscription may contain special characters, which allow you to subscribe to multiple topics at once
This should be
A subscription's topic filter may contain...
Lines 1339-1342 should say:
The topic level separator is used to introduce structure into the topic name. The wildcard characters can be used in topic filters, but MUST NOT be used within a topic name of a PUBLISH Packet.