I've searched the iCalendar spec https://www.rfc-editor.org/rfc/rfc5545 and the CalDAV spec https://www.rfc-editor.org/rfc/rfc4791 looking for insight on how to mark an event that is sent from our calendar server to an iPhone as "read-only" (non-editable) when the iPhone connects to our server using the CalDAV protocol. But the answer is not jumping out at me.
In other words, the iPhone user is receiving, via a CalDAV account a bunch of events. Normally, they can edit any of these events. However, we want to be able to mark a few as read-only. I know that we can use the iPhone ability to add an .ics subscription account, but we don't really want to do this, because it requires the iPhone user to add BOTH a CalDAV and an .ics subscription account.
We are using SabreDAV as our CalDAV server.
My technical co-worker has asked me to look into this, so I am asking for help from the Stackoverflow community.
Any help or hints will be greatly appreciated.