The Northern Ireland guidelines say:
Gatherings indoors or outdoors, not in a private dwelling, of up to 15 people are permitted.
The limit for gathering indoors and outdoors does not apply where that gathering has a recognised person responsible for organising or operating the gathering and it is organised or operated for a particular nature,, including those organised:
for cultural, entertainment, recreational, outdoor sports, social, community, educational, work, legal, religious or political purposes
Make of that what you will.