Ahhh, convocation! 

 that brings back memories of college....
We had dress codes at college (I attended an HBCU).  I know if someone came to class in pajamas, they would have been sent back home to change.  Not to say that you had to come to class in a Brooks Brothers suit but sweats or jeans would have been sufficient (unless it was school of business day - then you did have to dress up 

  ).