Dear Carolyn: My child will be married this summer. If the invitation states "cocktail attire," does that mean mandatory jacket and tie for men? We have a guest who is refusing to wear one — the boyfriend of the groom's aunt. What is the proper thing for the host to do?
— Proper
Proper: “Cocktail attire” says next to nothing about what the dress code actually is. It’s not just a problem here, it’s a widespread burst of creative phrasing that broke a tradition that didn’t need fixing. Casual, semiformal, black-tie, etc., actually said what guests needed to do.
Anyway.
“What to do” about your ornery guest is nothing. Gracious hosts smile and welcome their guests and hope everyone has a good time.
Re: Dress code: We used "cocktail attire" on our invitations. I thought it was less confusing than semiformal, which I never really understood. One uncle wore a collared shirt with no tie or jacket. I don't believe anyone noticed or thought he was inappropriately dressed, but everyone sure noticed my aunt running around saying how embarrassed she was that he wouldn't wear a tie or jacket. Save your energy for the things you can control.
— Cocktail Attired
Cocktail Attired: Great point.
But. Formal: tuxedo. Semiformal: suit. Casual: casual . . . as if your future boss will be there. It’s quite straightforward. Emilypost.com has details.
Re: Dress code: As long as your guest keeps his pants on, he's good to go.
— Almost Had to Call the Cops
Almost Had to Call the Cops: There’s our dress code: Pants on.
(Source: Carolyn Hax column in The Washington Post, April 17, 2020)

Comments
LOL!
Glad it amused you!
Of course! Thanks for the morning grins.
Glad it amused you; I had to share :))
I was fortunate to have fared better, I suppose!
Agreed, she should've been more specific, I had specified "pale blue or lavender dresses", myself, and everyone got a suitable dress ;)