Patrick,
WELCOME TO THE AWS WELDING FORUM!!
Okay, now, maybe Al is a mind reader, or maybe I just missed something, BUT WHAT SEMINAR ARE WE TALKING ABOUT????
If we are talking about the CWI seminar and exam...Just casual, neat, modest, not distracting and/or disrespectful of others.
Some have come in slacks and dress shirts, jeans and tee shirts, shorts and sandals with tee shirts, dockers and polo shirts, etc. You get the point.
Hope I covered what you were asking.
Have a Great Day, Brent