Usually, we just give each other a kind and respectful reminder. If it is something consistent or thrown in our faces kind of thing, we have a Safety officer or other officers to help deal with it to include suspension from using the field. This is something that should be addressed in your By-laws . We have denied people the use of the field because they did not have proof of AMA , Continually do not have proof, which is a requirement, We have also made exceptions , one of the rules is you have to attach your AMA card to the Frequency flag, Helps with checking none club member use of the field.