@Lilleberg said in MMM-CalendarExt3:

I want to display a symbol in front of a specific calendar events. I have one calendar for all the birthdays during a year, and I want for example a cake as a symbol in front of all the events from this specific calendar. All the other calendars should be without a symbol.

You can assign a symbol to the specific calendar on the default calendar module’s configuration, not MMM-CalendarExt3’s.

Or you can transform data of event itself by eventTransformer property, like this;

I recommend prior.