"Named Additional Insured"... My guess, unless you've rented a pitch for training or matches, you have no idea what that's asking.
Most decent General Liability policies carry an endorsement called "Blanket Additional Insured." Typically, this means that if you have a contract/written agreement with a facility, then the facility would be included under your insurance policy. (See you contract for specific details....)
However, many municipalities and school districts want to be named ON the policy, the "Blanket Additional Insured" ain't good enough for them... This could add extra premium to you costs.
Trick: Go into the quote process with a LIST of venues. Figure out which want to be named, and which are cool with just a Certificate of Insurance, or COI. That'll save you huge $$$ and TIME....