As a result, if you are a woman wearing a casual cap that is not a "fashion hat" and is part of your clothing, you should remove it as advised above for guys. Men may make an exemption if they are attending a costume party or event. You may wear your hat or head covering indoors if it is part of your costume. For example, if you are dressed as a nun, you would not need to remove your religious head covering. However, if you are at a party or event where there is no costume involved, being well-dressed does not require a hat or head covering. If you feel uncomfortable without a hat on, you can always bring one with you. In general, if you are having fun at a party or event and want to fit in, you should avoid wearing a hat that is too formal or old-fashioned. A baseball cap is very popular among men today and is never inappropriate to wear to a party. However, other types of hats such as panamas and fedoras are more appropriate for special occasions. At a party or event, you should remove your hat when entering a room or area where people are sitting or standing. This is especially important if you are the only person in costume. People will know that you are not supposed to be wearing your hat and could ask you to take it off.