Some Marvel fans think they have spotted a key plot point for the next Avengers movie... on IMDb.
The Internet Movie Database is generally more reliable as a source for movies that have already come out -- or which have, at least, already had their official credits released. Anyone with a professional account can edit the site, and it is often a source for unverifiable and/or incorrect information.
That said, a pair of minor Avengers: Endgame roles currently listed as "70's Car Girl #1" (Monica Mathis) and "1970's Scientist / Lab Worker" (Miles Webb) may, if accurate, suggest that the movie goes to the decade of disco.
Since time travel has long been assumed to be a part of Avengers: Endgame by certain segments of fandom, the potential for a scene set in the 1970s has those people saying that the fan theories are all but verified, but it is probably worth remembering that the Marvel Cinematic Universe has yet to use time travel despite having explored other eras, from Captain America: The First Avenger and Agent Carter to Captain America: Civil War and Captain Marvel. Basically, anything with "Captain" in the title. You get the idea.
The bottom line: it is distinctly possible that someone or a pair of someones broke the rules and posted something they were not supposed to on IMDb. It is equally likely that these listings are incorrect, outdated, or false spoilers planted to get fans talking.
Those who have been around for long enough will remember that when Marvel's The Avengers was heading into theaters, an IMDb listing had plenty of people convinced that Cobie Smulders' Maria Hill was going to secretly be a Skrull. That didn't happen.
...Or did it?! After all, Captain Marvel is going to introduce Skrulls soon. Just how deep does the rabbit hole go, Robin Sparkles?!
Avengers: Endgame stars Robert Downey Jr. (Iron Man), Chris Evans (Captain America), Josh Brolin (Thanos), Scarlett Johansson (Black Widow), Chris Hemsworth (Thor), Jeremy Renner (Hawkeye), Brie Larson (Captain Marvel), Danai Gurira (Okoye), Evangeline Lilly (The Wasp), Paul Rudd (Ant-Man), Karen Gillan (Nebula), Mark Ruffalo (Hulk), Don Cheadle (War Machine), Bradley Cooper (Rocket Raccoon).
Avengers: Endgame enters theaters on April 26th. Before that, fans can travel to the Marvel Cinematic Universe of the '90s with Captain Marvel in March.