Negative Commandment #21
Sefer Ha’mitzvos Ha’Katzar (The concise book of mitzvos)
By the Chofetz Chaim
This book lists the Torah mitzvos that can be observed today
Second Section – the Negative Commandments
21. It is a negative commandment not to walk in the ways of non-Jews
As it states in Vayikra (Leviticus) 18:3, "Do not walk in their ways." A person should not dress in clothing that is unique to them nor grow his hair like them. Neither should he not cut off all of the hair on the side of his head leaving only the hair in the middle, which is called "Veloris", nor cut his hair that is opposite his face, from ear to ear, and leave a growth in the back. Anyone that does any of these or like them, receives lashes. A person, who is close to the Government officials and is required to dress in distinctive clothing, is allowed.
This applies in all places and at all times, for men and for women.