Winter Dress Blue is considered a dress uniform. It is suitable for all situations the Tropical Blue uniform is – meetings, classrooms, and public events. The uniform shirt, known colloquially as the CPO shirt, can be hard to find as the shirt is a Coast Guard only uniform item (unlike the other shirts which are shared with the Air Force). It presents a sharp look and is considered a dress uniform suitable to substitute for the Service Dress Blue, unless a jacket is necessary. Besides the ODU, this is the only uniform which is identical between the sexes.