I do almost exclusively special event coverage. We do what is needed for the event based on risks anticipated, so there is no template that is always followed pedantically every time.
Small events get a first aid station. More wilderness/park events might get bicycle ambulances and golf cart ambulances. City events get walking teams and aid stations, and at larger events reciprocal communications with Fire Department. We always have our own radios for each team member, a way to communicate with event staff, and a link to the 911 system if we need ALS and/or transport.
Every team, cart, bike, or station has a trauma kit, oxygen, and AED, as well as basic first aid supplies. Each supervisor has triage tags, OBGYN kit, and other esoteric, low frequency items, and will respond when requested.
Law Enforcement typically asks us to deal with issues of missing persons and minors within the event. We also try to keep the event safe by providing water and sunscreen, etc, to those who need it.
Sometimes at a really big citywide event, the Fire Department will have us respond to 911 calls and triage those that actually need transport because ingress and egress is a real headache. We will either extricate the patient somewhere to meet ALS or clear a path for them to drive to us. In such a circumstance, calls are generated and incident numbers given from 911 dispatch, instead of from an event walkie talkie. This only happens about twice a year but is great fun.
The organization I work with now is strictly BLS but is extremely well organized and has good relations with Fire etc. A former organization I worked with also would do ALS field clinics, but their response and coordination, as well as interface with other agencies, was poor.
The one thing I like about my current group is general proficiency. We do monthly continuing education and drills to keep us ready in case Boston happens again at one of our events, or if we get a low frequency emergency.
Is there something specific I can go into detail about?