The text below shifts back and forth between "Topic Aliases" and "topic aliases". In general, it would be good to perform a capitalization consistency pass on the document for special names.

1468 This value indicates the highest value that the Server will accept as a Topic Alias sent by the Client. The
1469 Server uses this value to limit the number of topic aliases that it is willing to hold on this Connection. The
1470 Client MUST NOT send a Topic Alias in a PUBLISH Packet to the Server greater than this value. A value
1471 of 0 indicates that the Server does not accept any Topic Aliases on this connection. If Topic Alias
1472 Maximum is absent, the Client MUST NOT send any topic aliases on to the Server.