Composing a party invitation can be a bit baffling. Modern etiquette keeps evolving, and it’s hard to keep up with what is good manners and what isn’t. Just what should you include so guests arrive chill and ready to party?

“There’s no doubt that peoples’ sensitivities and norms are changing with the times,” says James Hirschfeld, co-founder and chief executive of Paperless Post, an online invitation source that sent out 70 million invites last year. Only a generation ago, he says, hosts would not have been asking about dietary restrictions or attaching gift registries. “But such are the times we live in.”

As entertaining has become less formal, invitation wording has loosened up. A lot of party details besides the date, time, place and host are being shared. Digital invites such as Hirschfeld’s and a host of others including Evite and Minted, plus Facebook, have replaced paper invitations for many.

What information is crucial? Daniel Post Senning, author and spokesman for the Emily Post Institute, says, “Give your guests enough information to respond well and participate fully.”

The list of awkward entertaining issues of modern times continues to grow. “You do have people who just show up for a party with a friend, and maybe even bring a dog,” Hirschfeld says. “I haven’t yet seen ‘Your Dog is Not Invited’ on an invitation. But it’s only a matter of time.”

We invited Hirschfeld and Senning to comment on five topics often addressed in invitations: attire, gifts, kids, food and venue. Here are some do’s and don’ts to keep in mind.

Attire: Be creative but clear

Guests appreciate knowing whether an event is jeans and sweaters or black-tie glam. But there is so much in between, such as “dressy casual,” “come as you are” or even “1980s hair metal.”

“Making the information useful helps guests participate better. But whatever you say should match the tone of your event,” Senning says. Stick with the standard etiquette rules for a serious soiree such as a wedding. “But if your party is about having fun,” he says, it’s okay to “be creative about the way you word things.”

So feel free to go with “snappy casual” if you don’t want guests showing up in jeans and T-shirts, or “ugly Christmas sweater” for a spirited holiday gathering.

Hirschfeld says that to inspire guests, some hosts link attire to a Pinterest page of possible outfits or costumes. “It helps people get in the mood and figure out what they should be looking for,” he says. The key is to either be specific or just mysterious enough to inspire fun dress. Usually something like “smart casual” can be decoded among friends, he says.

Does “cocktail attire” always mean a tie for men? Not necessarily — probably a jacket, though, Senning says. Communicate what you’d like the tone and spirit of the party to be. “If you want people to wear a tie, then just say ‘jacket and tie’ on the invitation,” he says.

Venue: Put guest comfort first

Senning says he’s all for thinking about guests’ ease and convenience. “If the party is going to be outside, let people know in advance,” he says. They might want to bring some bug spray.

Give essential information, but don’t go overboard. “If you are having a simple birthday party, don’t send out something that has a user instruction manual that feels like you’re going to fly a 747,” Hirschfeld says. For example, there is no need to suggest using Uber in a major city — it’s ­self-explanatory.

But if there is something that may affect the comfort of your guests and their experience, let them know in advance. Hirschfeld says. “Have some fun with it. For example, if you’re having a garden party, you could write: ‘Ditch the heels and bring a layer.’ ”

Food: Ask about preferences

Inquiring about dietary restrictions is common in an invitation and is totally acceptable for any kind of lunch or dinner event, experts say.

Common ways of handling it in an invitation are: “Please let us know of any food allergies/needs/restrictions/preferences.”

“ ‘Let us know if you have any special dietary needs’ is a nice way of asking,” Hirschfeld says. “More and more, people are careful about what they eat. What could be worse than inviting someone to your house and cooking a prime rib roast, then you find out they are vegan?”

Senning says you aren’t obligated to put anything about food in the invitation. “But I do like the idea if you are willing and ready and able to make accommodations, and you suspect there are some people who might have an issue, that you include it.”

Kids: You can (kindly) say no

The subject of kids is a hot- button one, Hirschfeld says. “People in their 30s who socialize with each other, some have kids and some don’t. It’s touchy,” he says. Be considerate. If your friends tend to spend most of their weekend hours with their children, they will have to figure out a babysitter, so give notice well in advance. A nice way of saying it on the invite without being harsh: “While we love your kids, this event is adults only.”

Senning advises: “I would say, ‘adults only’ versus ‘no kids’ on the invite to go for positive framing. You aren’t saying you dislike children, but it indicates, ‘I’m looking forward to enjoying your company.’ ”

Gifts: No mixed messages

Letting guests off the hook for gifts gets a bit tricky. It’s not necessary for many kinds of parties (such as a Super Bowl watch party), and not everyone will honor your request anyway. But feel free to express your desires, clearly.

“We see people putting mixed messages in their invitations,” Hirschfeld says. “If you really don’t want any gifts, just say that; don’t later suggest making a donation to a charity.”

And of course, do not link to a gift registry after already saying no to presents.

Senning cautions not to put “no gifts” for dinner parties or afternoon barbecues, or any event where people wouldn’t really be thinking of anything other than the usual small host or hostess token. That sort of request implies you were expecting presents in the first place.

On the other hand, if you put “no gifts,” be gracious, and don’t scold anyone who brings one. “If they do show up with a gift, don’t say, ‘I told you not to,’ ’’ Senning says. “Just receive it nicely, and say thanks. You don’t have to do the opening in front of them. Open it later and then thank them for whatever it is.”

And if you do want gifts?

Hirschfeld says, “If you’d like to signal that gifts are welcome at your housewarming you could say, ‘Your presence is present enough. However, should you like to give a gift to help us feather our new nest, we are registered at Williams Sonoma, etc.’ ”

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