The naval or military uniform that is specified by regulations to be worn on ceremonial occasions WordNet 3.0 & Open English WordNet

Full dress uniform is the most formal military uniform reserved for parade or other ceremonial or formal occasions. Wikipedia

Full dress uniform, also known as a ceremonial dress uniform or parade dress uniform, is the most formal type of uniforms used by military, police, fire and other public uniformed services for official parades, ceremonies, and receptions, including private ones such as marriages and funerals. Wikipedia

Most formal military uniform, used for parades and other formal occasions Wikidata

Uniform for wear on formal occasions Wikidata

Clothing worn on formal occasions. Wiktionary

The most formal military uniform worn by a member of the military for a formal occasion, corresponding to the civilian white tie dress code. Wiktionary

Clothes worn by a member of the military for a formal occasion. Wiktionary (translation)