What Is the Dress Code at Dunder Mifflin?

As someone who works in an office for the first time, I'm interested in understanding more about Dunder Mifflin. At the moment, I'm wondering if the office dress code is business, or business casual?
  1. Michael was always dressed in a suit and tie
    This could very well be because he's the boss. Maybe management had to always be in business attire while others had more choices?
  2. Jim always had a shirt and tie, but no jacket
    This could be because of his slacker, rebellious attitude. Or perhaps he didn't have to have a suit jacket because they were slightly more casual in the bullpen
  3. When Jim was co-manager, he did wear the whole suit
    Further giving credence to my management wears suits no matter what rule
  4. Toby also wore suits, more than likely because as HR, he was management too.
    Poor Toby.
  5. Pam is allowed to wear sneakers
    Now, my office is business casual, and we can't wear sneakers except on casual days. So, where does this fit in? She otherwise dresses business casual, I believe.
  6. Andy was somewhere in the business casual range, I believe.
    I think this is up high on the business dress list. He definitely knew how to throw together a wardrobe!
  7. What is this?
    @bjnovak played the many stages of Ryan perfectly. But I have no idea where this fits into office policy!