Everything written after 9 p.m. local standard time (emails, texts, Facebook messages, etc.) must be approved by an objective party in order to prevent the sender's potentially profound regret the following morning.
Example A
Mike: I still love her, man. That's it, I'm sending her a text right now to tell her.
Aaron: Whoa there. It's 11:30, the Rule of 9 is in effect. Hand over the iPhone.

Example B
Alison: My boss is such a bitch. I can't take it anymore, I'm sending in my resignation right now.
Jill: Rule of 9; back away from the laptop. You'll thank me in the morning.
by PookiePookiePookie Mama July 26, 2011
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Always carry a knife

(originated from S.A. Gibbs' unwritten list of Rules, as per NCIS)
AGENT: Thank god for Rule 9! Now I can cut off these ropes!
by MissNoodles June 23, 2006
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From NCIS tv show agent Gibbs. Always carry a knife.

A rule worth knowing.
What if I get into something i can't get out of. ....

Rule 9 : always carry a knife, you can cut yourself out of anything.
by nothing is real January 23, 2016
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There is no rule 11
Guy:..... Wait where is rule 11?
Guy 2: Rule 9
by Dr. Crowley January 24, 2010
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there is no rule #8
rule #9 is there is no rule #8
by xD13239 January 7, 2012
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If you are out riding in bad weather, it means you are a badass. Period.
The wind was howling and the rain bounding the tarmac, but a baddass bunch of rule 9ers carried on pedalling through the shitstorm that is the British summertime.
by AD828321 June 7, 2020
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