
The One With Princess Consuela - S10-E14
Continuity mistake: When Phoebe and Mike are at Central Perk discussing their name changes, his scarf goes from being hung loose around his neck to tied around his neck from shot to shot. (00:12:15)

The One With The Cake - S10-E4
Continuity mistake: Just before Rachel and Ross come back from the cake store, Monica is holding Emma on her lap. Emma is holding a green toy in one shot, when the camera angle changes it is nowhere to be seen. (00:19:30)

The One With The Cake - S10-E4
Continuity mistake: At the end after Rachel and Ross have come back from the cake store, when they are asking Emma how old she is, we can see Joey walking to sit down, then in the next shot he is sat down, then walking to sit down again. (00:20:25)

The One Where The Stripper Cries - S10-E11
Continuity mistake: When Ross and Chandler are talking about who broke which pact in college (the girls they agreed not to date) they are standing at the drinks table. Chandler is holding a drink in his left hand and his right hand is in his pants pocket. The shot then changes to face Ross, Chandler does not remove his hand from his pocket, but in the next shot facing him his drink is in his right hand. He then places it on the table. (00:18:20)

The One With The Cake - S10-E4
Continuity mistake: When Monica's mum and dad are leaving the party, they are standing next to each other while her dad explains why he can not drive anymore. Her mum has both hands in front of her holding on to her purse, in the next shot one arm is around Monica. (00:13:50)

The One With Ross's Tan - S10-E3
Continuity mistake: At the start, the lid on Joey's bottle is on and off depending on the shot. (00:00:20)

The One With Ross's Tan - S10-E3
Continuity mistake: In the scene where Joey and Rachel are sitting on the couch in their apartment after they decide their relationship is hopeless Rachel puts her head on Joey's shoulder. Her hair is on her face but when she lifts her head up in the very next shot her hair is now behind her right ear which she couldn't have done because her hands never left her lap. (00:22:00)

The One With Phoebe's Rats - S9-E12
Continuity mistake: At the party, when Monica and Rachel are talking about Gavin, Rachel has a napkin in her hand at one shot, the shot changes and the napkin is replaced by a drink. (00:13:20)

The One Where The Stripper Cries - S10-E11
Continuity mistake: When the girls and Mr Goodbody are talking about paying him the three hundred dollars, the top buttons of his shirt are ripped open. Half way though the scene this changes to only one button being open and his shirt looking neat and pressed, as if he had not started his strip yet. (00:13:25)

The One With Ross' New Girlfriend - S2-E1
Other mistake: After Rachel takes the phone from Ross and hangs up on Julie, when she's sitting at the table there's a bottle of Evian water in front of Monica with part of its brand name covered - the letters "e" and "n" are whited out leaving "via" on the bottle.

The One with the Sonogram at the End - S1-E2
Continuity mistake: Toward the end of the episode, the exterior shot of Central Perk shows about 8-10 people inside the cafe, at the coffee bar, at the tables. But the next interior shot shows the cafe is empty except for our six Friends, lounging in the closed cafe while Rachel cleans up. (00:12:15)

The One with the Blackout - S1-E7
Other mistake: When Ross and Rachel are out on the balcony alone for the first time, there are no lights on in NYC apart from candle lights. Look in the BBQ behind them though to see a very bright and very white light reflected in the paintwork. (00:13:50)

The One Where Ross Got High - S6-E9
Continuity mistake: When Phoebe finishes telling Rachel about her thanksgiving dream about Jack, Chandler is looking straight ahead with his arms crossed. Cut to the next shot when Jack and Judy are coming out of Monica and Chandler's room, and his arms are immediately uncrossed and he's looking at the women. (00:20:05)

The One with the East German Laundry Detergent - S1-E5
Character mistake: Janice enters Central Perk with a large shopping bag and even shows Chandler what she bought but when she leaves a few hours later, she leaves without it.

The One With The Soap Opera Party - S9-E20
Other mistake: In the opening credits, the word "Teleplay" is misspelled as "Telelplay."

The One with the Monkey - S1-E10
Continuity mistake: Just before the opening credits, when Ross says, "That's 'pathet', which is Sanskrit for 'really cool way to live', " Marcel is sitting on Ross's left shoulder in the closeup, but in the next shot the monkey is suddenly sitting on his right shoulder, right before Ross walks off screen. (00:01:00)

The One with the East German Laundry Detergent - S1-E5
Continuity mistake: The positions of the mugs shift between shots.

The One with Two Parts: Part 1 - S1-E16
Continuity mistake: Towards the end, as Joey is leaving Central Perk, Rachel's posture goes from leaving over the back of the sofa with her hands clasped to standing up with her hands on the back of the sofa. (00:18:15)

The One with Two Parts: Part 1 - S1-E16
Continuity mistake: When Rachel says about the name being the same in Spanish and English, the way she holds her chopsticks changes between angles. (00:06:10)

The One with Two Parts: Part 1 - S1-E16
Other mistake: When the woman in blue walks into Chandler's office, the camera pans back a bit too far showing the edge of the set. (00:05:20)
Answer: These are references to the TV show NYPD Blue. Deputy Andy Sipowicz is the name of one of the characters, whilst another character (Deputy Danny Sorenso) is played by Rick Schroder who previously starred in the show Silver Spoons.
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