Button-Down Collar Stays Buttoned

Dear Dr. Dave & Dr. Dee,

I have been told by some, that dress shirts with button-down collars should be kept buttoned when you are wearing a tie and leave the collar unbuttoned when not wearing a tie. Others have said the exact opposite. So, what is the "proper" etiquette for collar buttoning?

Signed,

Mr. Fashionable

Dear Mr. Fashionable,

Button-down collars on shirts normally stay buttoned with or without a tie. Also, the type of knot for the tie should be the narrower knot called the Four in Hand Knot, rather than a Windsor knot.

Button-down collared shirts are for more casual functions where a sport coat is acceptable.