I do not know this was mentioned, Bobby Rush violated a rule from 1837, rule 377 that “No member wear a hat during a session”,
http://books.google.com/books?id=CdBQ_yuiDAoC&pg=PA194&lpg=PA194&dq=1837+law+wearing+hats+in+the+house+of+representatives&source=bl&ots=gWcfotH8pB&sig=l1vAbxruaJiUsiWwFxW9vhUZpI8&hl=en&sa=X&ei=l7NzT8zjJYOG2gWUhpDuDg&ved=0CCQQ6AEwAQ#v=onepage&q&f=false
Clause five of rule 17 prohibits the wearing of hats in the chamber when the House is in session.