What happens at the Carlyle is never spoken about at the Carlyle — or outside the Carlyle.

“We don’t talk about our guests,” one longtime staffer says in the fascinating and delightful documentary “Always at the Carlyle.”

“I would never answer that,” says another employee.

Another veteran literally backs away from the camera while laughing lightly and waving off an attempt to get more information about a rumor involving a certain president and a certain movie star.

“What happens here stays here,” says another employee.

And yet here we have this insightful and occasionally revealing look at the 88-year-old Manhattan institution where the rich and famous enjoy being rich and famous.

In between sit-down interviews (almost all of them conducted at the hotel) with Carlyle loyalists George Clooney, Tommy Lee Jones, Anthony Bourdain, Lenny Kravitz, Sofia Coppola, Rita Wilson, Harrison Ford, Jon Hamm and I think you get the idea, writer-director Matthew Miele seasons in black-and-white photos and semi-grainy color film footage of former guests ranging from John F. Kennedy to Nancy Reagan to David Bowie to Princess Diana to Prince William and Kate Middleton, who stayed at the Carlyle on their first visit to the States as a couple in 2014.

Yes, this is like an extended episode of that old “Lifestyles of the Rich & Famous” TV show, and some might find the subject matter tone-deaf for the times. But “Always at the Carlyle” is as much a celebration of the longtime staffers (some of whom have worked there for five decades) and their incredible work ethic and loyalty as it is about Jack Nicholson and Naomi Campbell and Mick Jagger lapping up the luxury back in the day.

Tommy Rowles has been serving up drinks and stories at the hotel’s famous Bemelmans bar for some 30 years. Danny Harnett has been a bellhop since the early 1960s. Dwight Osley has been a concierge pretty much forever. They love their jobs and they speak with great fondness of the clientele.

Longtime concierge Dwight Osley stands in front of the venerable Carlyle hotel in New York.

Longtime concierge Dwight Osley stands in front of the venerable Carlyle hotel in New York. | GOOD DEED ENTERTAINMENT

And yes, it’s also great fun to hear all these familiar folks talking about the Carlyle.

“It has a beautiful, iconic New York feeling,” says Jon Hamm. “If you stay here, you feel like you’ve made it.”

Pause.

“I’ve never stayed here.”

Harrison Ford gives an interview in a room that goes for $1,100 a night — and is told he won’t be able to stay there that evening because it’s booked.

George and Amal Clooney have stayed at a suite that goes for a lot more than $1,100 a night. Jack Nicholson, were told, sends orchids to a certain favorite employee every time he stays at the Carlyle.

Director Wes Anderson talks of Bemelmans having an influence on the style of “The Grand Budapest Hotel.” Director Sofia Coppola talks about basically growing up in hotels as a child, and how the Carlyle was a favorite.

A former waiter talks of how Paul Newman occasionally ventured into the kitchen to make his own salad dressing. A few years after that, Newman was making a LOT of his own salad dressing.

Numerous staffers name Clooney as their favorite guest. Nobody says anything really bad about anyone by name.

At times the film feels like an extended promotional video for the hotel — except the hotel doesn’t need promoting. Either you have the means to stay there and you prefer the shabby-chic, old-school vibe, or you don’t.

As the story goes, Donald Trump brought a group into the Carlyle one night and after a brief tour was overheard saying, “This place is a joke.”

For some, that’s a gold-plated endorsement right there.

★★★

Good Deed Entertainment presents a documentary written and directed by Matthew Miele. Rated PG-13 (for some suggestive content, drug references and brief partial nudity). Running time: 92 minutes. Opens Friday at the Gene Siskel Film Center and the Wilmette Theatre.