A popular riddle about lawyers is:
 
Q: What do lawyers wear to court?
A: Law suits.
 
The pun/joke has been cited in print since at least 1998.
   
 
Google News Archive
12 December 1998, Gadsden (SC) Times, “Mighty Funny’s Mini Jokes,” The Mini Page by Betty Debnam, pg. B5, col. 4:
Q: What did the lawyer wear to court?
A: His lawsuit!
(sent in by Suzanne Brown)
 
29 November 2000, Los Angeles (CA) Times, “The Kids’ Reading Room; Reading by 9; Jokes & Riddles,” pg. E7:
What do lawyers wear when they go to court? Lawsuits. (Gaby, 8, Warner Avenue Elementary, Los Angeles)
 
Google Books
April 2001, Boys’ Life, “Think & Grin,” pg. 62, col. 2:
Gus: What do lawyers wear to court?
Russ: What?
Gus: Lawsuits.
—Sam Watt, Alton Ill.
 
Google Books
The Gigantic Book of Riddles
By Jacqueline Horsfall, Lori Miller Fox and Joseph Rosenbloom
New York, NY: Main Street
2004
Pg. 217:
What do lawyers wear to court?
Lawsuits.
 
Google Books
The Mammoth Book of Really Silly Jokes
By Geoff Tibballs
London: Constable & Robinson Ltd
2011
Pg. 346:
What do lawyers wear to court?
Lawsuits.
 
reddit
What do lawyers wear to court?
submitted January 10, 2016 by HavikWolf
Lawsuits!
   
reddit
What do lawyers wear to court?
submitted June 15, 2016 by t0pax
Law suits.