<P> In the US Army, evening mess uniform, in either blue or white, is the appropriate military uniform for white - tie occasions . The blue mess and white mess uniforms are black - tie equivalents, although the Army Service Uniform with bow tie are accepted, especially for non-commissioned officers and newly commissioned officers . For white - tie occasions, of which there are almost none in the United States outside the national capital region for US Army, an officer must wear a wing - collar shirt with white tie and white vest . For black - tie occasions, officers must wear a turndown collar with black tie and black cummerbund . The only outer coat prescribed for both black - and white - tie events is the army blue cape with branch color lining . It is a faux pas to wear white - tie equivalent evening mess uniform for a black - tie event . </P> <P> Certain clergymen wear, in place of white - tie outfits, a cassock with ferraiolone, which is a light - weight ankle - length cape intended to be worn indoors . The colour and fabric of the ferraiolone is determined by the rank of the cleric and can be scarlet watered silk, purple silk, black silk or black wool . For outerwear the black cape (cappa nigra), also known as a choir cape (cappa choralis), is most traditional . It is a long black woollen cloak fastened with a clasp at the neck and often has a hood . Cardinals and bishops may also wear a black plush hat or, less formally, a biretta . In practice, the cassock and especially the ferraiolone have become much less common and no particular formal attire has appeared to replace them . The most formal alternative is a clerical waistcoat incorporating a Roman collar (a rabat) worn with a collarless French cuff shirt and a black suit, although this is closer to "black - tie" than white - tie . Historically, clerics in the Church of England would wear a knee - length cassock called an apron, accompanied by a tailcoat with silk facings but no lapels, for a white tie occasion . In modern times this is rarely seen, however if worn the knee - length cassock is now replaced with normal dress trousers . </P>

Can you wear a white tie to a black tie event