Identifying helicopters from the Fire hose

I know I can look at aircraft type, however, this is not very practical as it requires that I know the type of aircraft I am looking for. What if I wanted to get all/any helicopter from the fire hose? I don’t know all the helicopters in existence and therefore I cannot create a list to filter.

Does anyone have any suggestions?

ICAO Doc 8643 may be useful to you.

Thanks. I managed to figure out how to query their system to retrieve my answer, via code.

How about a tutorial for us ( newbie ) chopper spotters?