Missionary Position: A sandwich with only three ingredients: cheese, bread, and butter, but any or all of the ingredients may be flavored differently from traditional. This does NOT mean additional ingredients, only flavored ingredients. Infused butter is fine. Cheese with herbs in it is fine. Adding a sprig of herbs to your sandwich as a fourth ingredient is not fine.
Examples of past winners in this category are Moon Unit - walnut-raisin-pumpernickel chevre and cave aged gruyere, or The Black & Tan, composed of marbled rye and porter beer-marbled white cheddar. Or the Cheeses Crust: homemade white cheese on homemade white bread.
Still confused? Ask The Authority.