Never saw any hats that indicated anything other that they wanted to cover their head or hair. I suppose you could wear a symbol indicating you orientation or lifestyle on a t- shirt and that would be easier! The full swap swingers were generally easy to spot but harder to discern other varieties of lifestyle people. Sometimes you simply have to ask - no body should be offended.
Better take those spears off my flip flops then. People wear all kinds of hats. Donald what are you saying about my fireman's hat.