A rule requires no advance preparation. Given a sufficiently clear dress code, you shouldnt need to study the latest edition of Posts classic tome to understand the nuances of a particular social groups dress habits
These days, the newly-revived Juicy (because, yes, it's still kicking) makes velour track suits for all your leisure needsor, should you want to go the fashion-person route, you can splurge on a super-deluxe version by Vetements
Or if your office is on the cooler side, this may be a great option for you
A wool coat can be layered over everything for outdoor moments
The Armys military dress uniforms consist of a blue army coat, a white army dress shirt with long sleeves, a black necktie, and a beret