
and possibly the
Geneva Convention.
The Big Bang Theory Season 11, Episode 12

I'm starting my own CONVENTION.
The Big Bang Theory Season 7, Episode 14

Did you tell them that
you're holding your CONVENTION
The Big Bang Theory Season 7, Episode 14

...I finally arrived at the
Fourth Annual Dixie Trek Convention...
The Big Bang Theory Season 3, Episode 5

I believe that social CONVENTION dictate
you not arrive empty-handed.
The Big Bang Theory Season 3, Episode 6