“What do you call a book written in prison?”/“Context.”

A prison riddle was posted on Reddit—3amjokes on February 1, 2021:
     
Q: What do you call a book written in prison?
A: Context.
 
“Context” is a pun on “con text.”
 
   
Reddit—3amjokes
Posted by u/PatsterRedditster February 1, 2021
What do you call a book written in prison?
Context.
COMMENTS
pohpia
That must be a long sentence.
 
Twitter
Veep
@ValeriePiazza
What do you call a book written in prison? Context
10:15 AM · Feb 2, 2021·Twitter for iPhone
 
Twitter
𝓢𝓪𝓷𝓭𝓮𝓮𝓹
@cosmos_ipi
What do you call a book written in prison?
Context
11:10 AM · Feb 2, 2021·Twitter for Android