When using Web Sockets, this option allows control over how the server will respond to a close by the client.
When "yes" the session will not be closed if it is a close request from the client (the session can only be closed by navigation in the host screens to a point where the host closes the session and connection).
When "no" (default) then a close by the client will also close the host session.
Example:
<add key="WSKeepOpen" value="yes"/>