what is really unclear is this topic title
are you asking us "is business attire casual or formal"
or are you asking is "what constitutes casual or formal when it comes to business attire"
I assume the latter because the former is a ridiculous question, but man, what an unclear sentence.
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I'm "kind of a big deal".
http://img.imgcake.com/cyclo/Cyclopngegpngre.png