Anything the chef isn't comfortable cooking.
Most chefs will be honest about their limitations when planning a wedding menu, but some may over-promise and under-deliver. In order to avoid having false expectations, it's best to sit through a tasting with your caterer before signing off on the meals that will be served at your wedding. If you've asked them to make a customized dish for your cocktail hour or reception, this tasting is more important than you may realize.
Overly boozy cocktails.
Shots, shots, shots-no surprises here-are usually a bad idea at weddings. Prior to your reception, you may consider having a chat with the bar manager or catering team to ask that all booze be served with a mixer. Few wedding guests will ask for shots, but it's not uncommon for some people to request "extra strong" cocktails. To avoid a messy scene, it's best to talk with bartenders before the event about using a standard amount of alcohol in each drink.
Anything overpoweringly fragrant.
It often surprises couples when they walk into their wedding reception and find that the whole room smells strongly of food. A good way to avoid that happening on your big day is to stay away from menu options that are very fragrant. Food with a lot of garlic, onions, spices, and stinky cheeses can all overpower a room. Interactive cooking stations can pose a problem, too.
An all-buttercream wedding cake on a 90-degree day can quickly go from gorgeous to a melted disaster. Likewise, there are plenty of salads and veggies that wilt quickly if it's too cold. It's usually best to steer clear of incorporating weather-sensitive foods into the wedding menu. Cakes are particularly sensitive to temperature since they sit out on display for a while before being sliced, so it's a good idea to chat with your baker about the best options given the expected weather.
Options that won't appeal to most guests.
It's perfectly acceptable to get creative with your wedding menu, serving things like lamb and fish as entrées rather than chicken and steak. However, getting too experimental or forcing your own dietary style upon your guests isn't seen as good etiquette. Guests without dietary restrictions could feel intimidated by an all-vegan, gluten-free, dairy-free wedding menu. It's always good to have those options, especially if it's your way of life, but it's good etiquette to have some other, more approachable types of food that guests are comfortable with as well.