Navy Blazer argument and Student Intern help

Hello everyone,

Great forum. Much better than some of the others that I have been to and have already learned so much. I have a couple of questions that I hope you gentlemen and laides can help me with. I am currently a graduate student and will be working as a student intern in D.C. for the summer. The problem is that the HR person says that they maintain a 'business casual' atmosphere. Business Dress is easy, but this, come on! Any help that I can get on the questions below would be greatly appreciated.

1. Now my classmates and I are arguing about whether the classic BB navy blazer falls within this category, or whether it should stay in country club or cocktail casual. Can one wear a navy blazer in a business casual setting?

2. The HR professional said that everyone wears buttondowns and slacks, no jackets. Does that mean that I should not wear a tie? I don't want to wander around looking like an idiot wearing a tie without a blazer or sportcoat if this should not be done. Do dress slacks, buttondown, and long/bow tie fall within 'business casual' or 'business casual ignorant'?

3. Being from the south (Alabama) I have always worn bow ties, however, after reading many articles I have a sneaking suspicion that I should cease immediately, does anyone second that opionion or should I continue my love for them?

4. Can a navy knit tie be worn with grey toned slacks and a white buttondown?

Thanks so much in advance, I really appreciate bringing me to the light with this site. My parents gave me the Molloy book but it does not cover some of the more integral aspects of dealing with clothing like this site does. It is already on my Favorites list and is quickly becoming my classmates favorite forum for dress questions as well.

Keep up the good work!
J. Fields Collins