How to Exclude Rooms from Ringing
Login to Informacast and select Ricipents>Device Groups

Search for the Device Group you want to exclude a room from, (if you are not sure which device groups you need for the task go to ringlists under bell schedules and see what is used for groups thought the day)

For this example we will need to do this in GHH All Call and GHH Classroom Spaces as they are used at different times during the day.
Scroll down to devics to exclude and enter the excluded devices then hit save.

This will exclude them from ringing whenever this group is used in a bell schedule throughout the day. Remember if multiple device groups are used, you will need to add the exclusion to each device group that is used throughout the day in the bell schedule ring list.
You also need to set a reminder to go back in manually or move this override as it will stay in place until taken out manually.