i cant tell you straight out of the book or anything. but i live in richmond and carry a 3 1/2 blade and all the police ive encountered have been cool. but also i look normal and dont act like a fool generally. ive had a few comment that a folder clipped in the pocket is concealed and others say that the clip being exposed makes it not concealed. carry a 3 inch sheath knife too and never had any kind of problem.
so as far as i know: nothing over 3in folder, belt wear ok, no auto knives, or knives with a d-gaurd like trench knives.
but like i said in my experience, just be cool and leo's will be cool
i recommend that to stay out of trouble. thats what ive always heard from LEO's. but i dont know for certain. infact, the last time i was pulled over me and the officer were talking about concealed carry pistol permits and he did say it was a completely different permit for knives but that there were also very vague laws that dictate actual conceal carry of knives and he didnt know how to go about getting one (???- didnt help me much either). this is why i have the general notion that being an ok person LEO's are ok to you. still i wouldnt carry a sifu around like my buddy! -CB