instant messaging service
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... IMP-REQS] also stipulates that presence services must be separable
from instant messaging services; i.e., it must be possible to use the
protocol to provide a presence service, an instant messaging service ...
... instant messaging services; i.e., it must be possible to use the
protocol to provide a presence service, an instant messaging service,
or both. Although the text of this memo assumes that implementations
and deployments ...
... service must offer
both a presence service and an instant messaging service, and the
protocol makes it possible to offer separate and distinct services
...
... instant messaging, and is not required to support both if only a
presence service or an instant messaging service is desired.
...