WHEN TO WEAR EVENING DRESS:

from the order, page 1-28:

The officers' evening dress "A" uniform will be prescribed for official formal evening functions at which civilians would normally wear evening clothes or "white tie" during both winter and summer. The evening dress "A" uniform with white waistcoat for male officers and long skirt for female officers is appropriate for the following "white tie" occasions: State occasions at the White House, or at foreign Embassies/Legations, inaugural receptions and dinners, and formal dinners.

The officers' evening dress "B" uniform with scarlet waistcoat (general officers only) or scarlet cummerbund (all other officers) will be prescribed for official social functions at which civilians would normally wear dinner dress or "black tie" during both winter and summer. Females may wear the long or short skirt, depending on the degree of formality of the function.
The evening dress "B" uniform is appropriate for the following "black tie" occasions: club affairs, dinner parties, dinner dances, and evening celebrations in honor of the Marine Corps Birthday.

Officers not required and who do not possess evening dress uniform who attend functions at which evening dress is prescribed will wear the blue dress "A" or blue-white dress "A" uniform as appropriate for the occasion/season.

SNCOs may optionally wear the SNCO evening dress uniform in lieu of the blue dress uniform for social functions at which civilians would normally wear white or black tie during winter and summer.

The boatcloak is made of dark blue broadcloth material lined with scarlet wool broadcloth.  The The dress cape is made of dark blue polyester-wool tropical material lined with scarlet satin rayon cloth. Both are optional items which may be worn by male officers and SNCOs with evening dress and blue dress "A/B" uniforms for official and social functions. It will not be worn when the blue dress uniform is worn as the uniform of the day.

MCO 1020.34H pg 1-44

The standing white strip collar is worn by male officers with the evening dress and blue dress uniforms, the new female officer blue dress, and is attached in the inside of the coat or jacket with eyelet fasteners. The collar will have a straight edge high enough to extend not more than 1/4 inch above the uniform collar and will be long enough for the ends to meet in the front without a visible gap and with a slight overlap not to exceed 1/4 inch. 

MCO 1020.34H pg 1-48