Some of the rules imposed by the channel included making sure that "buttocks and female breasts are adequately covered" and avoiding "exposing bare fleshy under curves of the buttocks and buttock crack."
Perry, along with fellow singers , Alicia Keys and Jenifer Lopez, were the biggest violators of the night, and the trio went on to star in many "Grammy Dress code violators" headlines on Monday. But it was Perry's eye catching bust-line that got Elle DeGeneres attention.
The TV host was caught red handed while giving Perry's dress a "tasteful glance." Later that night DeGeneres came clean about her Katy Perry moment in a tweet.
"Here I am taking a tasteful glance at @KatyPerry's dress," she captioned a photo of the moment.