Photo by Liz West/CC License

Wedding etiquette plays an important role in planning for the big day, so couples shouldn’t overlook the significance of manners – from wedding invitations to the guest list and from thank you cards to the bridal shower. Emily Post is a great resource for everyone involved in wedding planning or invited to the memorable affair, including the bride, groom, family members and guests.

Even with social media, blended families and other unique situations, Emily Post provides valuable wedding etiquette advice that continually evolves. Founded in 1946, the Emily Post Institute studies the evolution of how manners change over time and vary depending on location and culture. The family business spans five generations. Peggy Post writes The Well-Mannered Wedding column for The New York Times.

Here she addresses a question from a reader regarding bringing the plus-one guest. Being polite and practicing good manners are always in style.

Who Deserves Plus-One Status?

My boyfriend and I have had several heated discussions regarding the etiquette of inviting guests with a plus-one. He thinks everyone should get a plus-one, all other factors aside. I think that only guests in a serious relationship (i.e. long term, living together) should warrant a plus-one invitation. Can you settle the debate?

Monica A., Berkeley, Calif.

Let’s avoid sending either one of you to the etiquette penalty box. Today’s standard plus-one is someone who is married to, engaged to, living with and, yes, in a long-term relationship with the invited wedding guest. Beyond these “must invites,” your plus-one decisions will be based on budget and consistency. If it’s only a few and it’s not a budget buster, you might consider asking them all. But if that’s not the case (and let’s be realistic here), come up with a clear parameter. Even so, without a plus-one invitation, some of your single guests may not want to attend. In the end, that’s their choice.

Note to guests: You didn’t get a plus-one invitation and you have a new boyfriend? Be empathetic and don’t take offense. Be happy that you’re one of the “must be there” people on the bride and bridegroom’s guest list.