Blend Images - Hill Street Studios/Getty Images Mustache haircut.
The Marine Corps standards of grooming require that hair be evenly graduated from zero length at the hairline with no outline or edging. Hair may not be over three inches in length or be styled in a manner that any hair protrudes from the scalp more than two inches. Hair must be styled so it does not protrude beneath properly worn headgear in an unsightly manner.
Sideburns may not be so long as to extend past the top orifice of the ear and may not be shaped so as to flare or come to a point.
The hair length of the sideburn may not exceed 1/8 inch.
Goatee and mustache name
Male Marines are not required to have hair clipped to the scalp all over the head, except when he is undergoing recruit training. A male Marine may shave his entire head.
Any unusual or trendy haircuts or styles are prohibited as they detract from the team uniformity. Hair must conform to the natural shape of the head without braids or spikes. Mohawks, teardrops, horseshoe flattops which leave large bald areas on top of the head. Etching or designs are not allowed. No unnatural hair colors are allowed. If hair color is used, the hair must complement the complexion.
Marine Facial Hair
The face of a Marine must be clean-shaven. The exception to this rule is that a mustache may be worn. The mustache may not extend past the corners of the mouth and its length may not exceed 1/2 inch.
Most Common Marine Corps Haircut
The popular choice of haircut, indeed the Marine's signature style, is the traditional high and tight haircut in which the hair is shaved clean on the sides and back up to the point where the head begins to round at the top.
The top of the head is typically cut clipper short and worn to conform to the shape of the head.