This may be useful for your Trumba users if you decide events on that specific calendar will not use event registration or you just want to simplify the Event Edit screen by removing the Event Registration tab.
To locate this setting, select a calendar from within the Publisher account and click the blue Settings button. Locate the Enabled Features section and by default Allow event registration is set to Yes. To hide the Event Registration tab, set this to No and then click OK.
When this setting is set to "No" on a calendar, the “Event Registration” tab is removed from the event edit form for events owned by that calendar.
The Event Registration link is also removed from the popup menu within Trumba for events owned by that calendar. This popup appears when you click on a blue drop down arrow within Trumba in front of the event title/date/time.
If the event registration tab is disabled on an existing calendar with existing events using event registration, existing events will not be impacted. Attendees can still register and the editor can still view registration details for the existing event but cannot enable registration on new events that are added to that calendar.