0 a private joke that can only be understood by a limited group of people who have a special knowledge of something that is referred to in the joke --
1 a joke that is understood only by a small group of people --
Part of the power of an in-joke is that its audience knows that there are those who do not understand the joke.
Frequent repetition gave it the status of a catch phrase or in-joke among the readership which continues to the present day.
Mathematical jokes are a form of in-joke, generally designed to be understandable only by insiders.
In fact, the bandages are a running in-joke.
An in-joke works to build community, sometimes at the expense of outsiders.
This had become a bit of an in-joke amongst those behind the podcast.
The song and video have since been used as a web culture in-joke on many different websites.
It has become something of an in-joke to buy the school clocks for classrooms.
