...you do not wear a baseball cap on your melon while sitting in a church or mission or just about any place of worship. No panama hats either.
...no matter how bored you are during the rehearsal, you do not put your feet up on the pew in front you & proceed to stretch your legs out fully using the pew as a foot/leg rest.
...you do not dip your hand in the water by the door just to see what it is and then flick the holy water off your hand onto the floor.
...you are not a bovine, please do not chew your gum and snap bubbles like a bovine during the entire ceremony and mass following.
...even if you are not Catholic and regardless of fashion trends of the summer you do not wear short shorts, old ratty capris pants, tevas, 99 cent flip flops good for shower shoes, skin tight tiny strapped tops that provided me with such a view I thought about the "plumbers crack joke", tubetop dresses (unless with a shawl or sweater while in the mission) or a tank top t-shirt with a cross bedazzled on it in bright shiny crystals in a mission that is so old that it was one of the original missions of California's El Camino Real.
At least no one took communion and spit out the host (or put it in their pocket).