Why is Jefferson Davis-Morales working for PDNY (instead of NYPD)?

Question

The movie Spider-man: into the Spider-verse focus on Miles Morales as the new Spider-man.

What surprised me when watching the movie is that his father Jefferson Davis-Morales is a policeman working for PDNY, not the iconic NYPD. This obviously stands for Police Department of New York, but the PDNY does not seem to exist.

The acronym can be seen in most scenes where Jefferson is on duty, like in the picture below, so it is difficult to miss and I am led to think it is intentional.

Is there any reason why Jefferson is not working for the NYPD?

The film is full of references to comics and previous Sony movies, so it may be a reference to a comic. But I couldn't find anything by googling PDNY.

My possible interpretations:

1. The multiverse and various versions of Spider-man are central to the movie. Maybe it is here to imply that Morales' universe in the movie is not our universe, hence that universe is not more important than the other universes (Spider-man Noir, manga version,...) that are depicted in the movie. The end of the movie hints a possible sequel.
2. The movie intentionally has some blurry images, where red and blue colors are not perfectly aligned, as a reference to comic books that are not always perfectly printed. Maybe the PDNY is an intentional typo, as a nod to typos in comics?

Any Word of God on the matter?

Answer 1

It's definitely a different universe. To quote the Alternate Universe TV Tropes entry for the movie:

• The Bland-Name Product(s) are this universe's equivalent to the brands they're clearly references to (as we clearly see during Alternate-Dimension Peter's world. The "Koca-Soda" sign we see in Miles' world is an actual Coca-Cola sign in Alternate Peter's).
• Similarly, near the end of the film, we see that Spider-Ham's universe has Porka-Cola.
• New York City's police department is given the acronym PDNY (Police Department of New York) instead of NYPD (New York Police Department). Conversely, the real-life FDNY (Fire Department of New York) is instead called the NYFD (New York Fire Department).
• Police vehicles aren't exempt from wearing registration plates, as seen on Miles' dad's police cruiser.
• The lights on police cruisers flash in red and blue instead of red and white.
• Snapchat is still called Picaboo, and Google is still called Backrub.
• The Blue Man Group is called the Red Man Group.
• T-Mobile became C-Mobile.
• A poster in Miles’ dorm room shows Chance The Rapper wearing a cap with the number “4” on it, instead of his signature “3”.
• An ad shows The Weeknd's "Starboy" cover design, but with his old persona's haircut.
• Taxicabs use the "NYC Taxi" livery design introduced in 2007 instead of the current black circle with a negative-space "T". In addition, taxis and police cars are made to resemble the older second generation Ford Crown Victoria, an increasingly rare sight as both since the model's discontinuation in 2011, but still a popular prop in film and television for its surplus availability.
• The current black-and-yellow "Empire Gold" licence plate design issued since 2010 and the previous white-and-blue "Empire State" issued from 2001 to 2010 are used simultaneously on some cars, also as seen on Miles' dad's police cruiser.
• New York is shown to be much larger in Miles' universe. In the first scene of the teaser trailer, much of the Manhattan skyline is taller than the Empire State building, currently the fourth tallest building in New York. Some of these skyscrapers are lit with projected advertisements.
• Miles doesn't know what Comic-Con is, suggesting it either doesn't exist in his world or it has a different name than the one in Peter's.
• The Yugo brand is alive in both Miles' and Peter's universe, as evidenced by a marketing campaign from a glimpse of Times Square with the tagline "It'll get you from A to B". Not bad for an infamous shorthand for The Alleged Car. For a background prop that appears for two brief scenes of the movie, the alternate-universe "Yugo" concept is modeled with considerable detail. In essence, it's a modern re-imagining on the original hatchback, complete with alloy wheels and a sleeker, more rounded appearance. As its most distinctive and jarring design choice, the car's front clip is modeled in direct reference to its inspiration, including two rectangular headlamps and a rectangular grille. Its bumper seems to be integrated into the body as a vent or a piece of black plastic trim.
• Golden State Warriors basketball legend Stephen Curry became a golf pro in Miles' universe, with a billboard touting him as "The Golden Boy" of the sport. (Truth in Television, as Curry is an avid and talented golfer in the off-season.)
• A Times Square billboard shows that basketball star Blake Griffin is instead an MLB player in Miles' universe (again, Truth in Television, as Griffin also played baseball before choosing to focus on basketball). The team he plays for is the New York Red Sox; in Real Life, that's Boston's team name, a nod to the notorious Red Sox/Yankees fanbase rivalry.
• Pop culture as Miles knows it is very, very different; on Spider-Man's arrival alone, we see advertisements for a jockey comedy starring Seth Rogen called Hold Your Horses, John Mulaney and Nick Kroll star in Hi, Hello instead of Oh, Hello, the proposed Shaun of the Dead sequel From Dusk Til Shaun was actually produced, there's a Clone High movie, and Bridesmaids is instead about baby showers.
• Doctor Octopus is a woman in Miles' universe, here named Olivia Octavius.
• The approval stamps on Miles' "True Life Tales of Spider-Man" comics are from the "Cabin Fever Production Code" rather than the Comics Code Authority.
• The Planet Hollywood restaurant and resort chain is called "Planet Inglewood." This also carries the implication that in Miles' universe, Inglewood is the heart of the American film industry.
• One of the posters you can see in the background is for EA Sports' latest Water Polo game. EA Sports is a real publisher (best known for the likes of FIFA and NBA licensed sports games), but they don't (at the time of writing) make a water polo game.

It's unlikely that it's a trademark issue. While it is true that that "NYPD" is a trademark, it's not one that's been defended aggressively, and I don't believe most movies pay to include it. Even so, this would have been fair use since it's not trying to confuse anyone into thinking this fictional police force in any way represents the NYPD.

Griffin added in the comments:

They also mentioned "PDNY" is used because it's an "alternate universe" in the Blu-Ray extras.

Dave Jacoby added in the comments:

Miles' uncle was old school, so when they go to the last untagged spot in the under city, they're playing his music: "Mary Mary" by Run-DMC, except it used a break beat from "Apache" by the Incredible Bongo Band, which in our world, didn't happen.