Option to hide Attendees in Shared Calendars

[NitramLegov]

Is your feature request related to a problem? Please describe.

We are running a public makerspace where we post opening hours on a public calendar so that people can see when we are open vs. closed.

Since we are having multiple hosts for our opening hours, we are adding the specific host to the calendar invite in order to enable them to see "their" events within their own calendars.

Unfortunately, on a public calendar within Nextcloud, the Mail Adresses of the attendees are publicly visible. I have not found a way to change this as a setting.

Describe the solution you'd like

Introduce a setting (either on event-level or on calendar / share-link level) to hide attendees on public links to a calendar

Describe alternatives you've considered

Using Google Calendar, since there is such an option

Additional context

No response

[tcitworld]

First of all this is harder that just hide attendees information in the UI since this data lies into the ICS calendar export.

It seems there's no standard way of doing this.
We could add a vendored value for CLASS, which would correspond to a "Only show basic information when published" for the "When shared show" event setting. Then we can filter out in ICSExportPlugin.

But using another vendored property may be better because you might want to have a classic value for CLASS at the same time.

Also, this applies to singular events, if we want to have this at the calendar level we need a CalDAV prop, but there's already a lot going on on this topic nextcloud/server#20096