1. One time, someone at Central Perk put a potato on the cake stand.
2. After the 9/11 attacks, the FDNY and NYPD were honored in several episodes.
3. In “The One With the Jam,” someone can walk behind Monica’s closet.
4. There’s an extra who looks like she’s chewing her coffee.
5. During Joey’s double-butt scene, there is a moving box with “Monica’s” written behind the crew.
6. The actress who plays Estelle was a nurse in the episode where Carol gave birth to Ben.
7. Ross and Emily’s wedding invitation has an extra “e” in Rachel’s last name.
8. When it takes Monica to open her wedding gifts, the big box goes from being wrapped to being unwrapped to being covered again.
9. When Pete sees Monica at work, he can see that the floor has padding for when she’s supposed to fall.
10. take a look at the “Reserved” sign on their “usual” table.
11. In the tenth season, Joey’s apartment has a massive hole in the wall.