Add the following text to the exposition on
/s:Envelope/s:Body/*/wse:Filter after the second paragraph:
It is possible for a Subscribe request to contain a
that will never evaluate to true for the lifetime of the Subscription.
If an Event Source detects this condition it MAY generate a
wse:EmptyFilter fault in response to the Subscribe request message.
Add the following fault definition to Section 6:
This fault MAY be generated when an Event Source detects a
wse:Subscribe request containing a filter that, for whatever reason,
will never evaluate to true.