At this time, I don't believe there's a way to add custom flags to calendar assets. May I ask what it is you're trying to accomplish?
What if I want to search the calendar for art exhibits or shows, dining, etc
We use sub-categories (sub-sections) within the Calendar section for that. You can use them to search, you can use them to create different blocks (to promote events in other sections), or to help users categorize their events upon submission.
Here is an example of the category dropdown on our main Calendar search:
where can I add the sub categories I looked and could not find this.
They are just sections and can be added in Settings -> Tags and then under Calendar.
Our customer support would be happy to help you set this up. Please contact our customer support team at 800-293-9576, or by submitting a request via our ticketing system. Thanks!
Customer support service by UserEcho