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1.
There will always be more rules. Always.
Dude 1>Dude, i just finished learning all the Internet rules.

Dude 2> Rule 51
by DoomB January 14, 2011
 
2.
Sometimes, you're wrong.

"Rule Fifty-One" was the title of the 7th season finale of the TV show "NCIS," referring to Special Agent Gibbs' established 50 rules for being a special agent of the Naval Criminal Investigative Service. At the end of the episode, in which he needed a lawyer, he went through a box with pieces of paper on which he'd written his rules, and one said, "#13 NEVER, EVER INVOLVE A LAWYER." He turned it over and wrote, "#51 SOMETIMES YOU'RE WRONG." A major admission for Gibbs, even to himself. If he can admit it, we all can.
DiNozzo: "Well, Ziva, it's like Ben Affleck said in 'The Hunt for Red October'... "

McGee: "Tony, Affleck didn't start playing Jack Ryan until 'The Sum of All Fears.' Alec Baldwin played Ryan in 'Red October.'"

DiNozzo: "Seriously, McGeek? YOU are challenging ME on a movie reference? I'm always right about these things, especially when Sean Connery is in the movie!"

Gibbs (slapping DiNozzo on the back of the head): "Rule 51."

DiNozzo: "Ow! Oh yeah: 'Sometimes, you're wrong.'"
by UncleMikeNJ July 07, 2011
 
3.
A rule stating that any swear word or phrase can and should be be replaced with DragonBall Z characters, when in the presence of siblings.
1: My printer just died!!!!1!1111!!!1!! NAMEK!

2: What?

1: Little sis is in the room, rule 51.
by Mottman August 22, 2010