Polycom RMX 1000 User Guide
•For an HD conference, the system does not provide the message overlay function.
•The message overlay set at the Participant Properties page supersedes any message overlay set on the Conference Properties page. When the two settings conflict with each other, the message overlay on the participant’s endpoint screen is displayed as follows: The participant’s message overlay, even if set later than the conference overlay, immediately replaces the conference level message overlay. The conference level overlay will not be displayed until the participant level overlay is finished displaying.