inside joke

a joke that only certain people understand; a joke understood only by people who know certain facts and context. What you said must be an inside joke. It makes no sense to me.

Common Names:

Name	Pronounced	Usage
Angelos	-	Greek
Alfhildr	-	Ancient Scandinavian
Kotone	ko-to-ne	Japanese
GrÍMhildr	-	Norse Mythology, Ancient Scandinavian
Inderjeet	-	Indian (Sikh)
Lysimachus	-	Ancient Greek (Latinized)