Continuity mistake: When Hank's trying to convince his dad to let the Vietnam vets join the VFW, the table behind him with the bowl of fruit and the vase of flowers on it disappears between shots. (00:12:45 - 00:13:15)
Returning Japanese (1) - S6-E21
Continuity mistake: On the plane whilst Bobby is watching the TV in front of him, you can see a man to the left of Bobby and an empty seat to Bobby's right. The seat arrangement looks to be like the middle row of seats where there is 3 seats instead of two. After the shot shows footage for the "Haiku" movie the shot changes to Bobby and the man sitting next to him but there is now no empty seat next to Bobby. It appears that he is now sitting at a window seat.
Continuity mistake: When Hank's trying to convince his dad to let the Vietnam vets join the VFW, the table behind him with the bowl of fruit and the vase of flowers on it disappears between shots. (00:12:45 - 00:13:15)
Continuity mistake: When Hank and the family are approaching Cotton's table at the rummage sale, there are two empty knife sheathes and one sheathed knife on his table. In the next shot, there are 3 sheathes and 2 knives out of the sheathes. (00:03:25)
Continuity mistake: After Peggy throws the tomato at King Philip you see it lands on the badge on his jacket. Most of the tomato lands about the top of his badge and seems to set on the top part. A few scenes later when Peggy is being put in the stocks for punishment you see Philip again and the stain has moved down the badge. Most notably the tomato stain looks larger and a large chunk of it has moved below the badge onto the shirt.
Answer: If you are talking about the "Thou shalt not do this, thou shalt not do that" song, I'm not sure if a song like that actually exists. Green Day, the guest voices on the episode, might have just been improvising to keep their appearance from being too obvious.