The outfit for training in Taekwondo is known as a dobok in Korean (literally do meaning "way", same as the last word in Taekwondo and bok meaning clothes). This is a pullover the head v-necked white uniform made of cotton or a modern cotton mix with a white collar for coloured belt or kup grades, a red and black collar for junior black belts or poom grades and a black collar for black belt or dan grades.
Other martial art uniforms are not acceptable. During the first couple of months of training, a t-shirt and jogging bottoms or shorts is acceptable, but past the first couple of months a proper Kukkiwon Taekwondo dobok is required.
The belt (ddee in Korean) is worn around the waist twice and tied neatly in a specific way. This is described below:
Taekwondo shoes may be worn (these should be bought from the club to ensure they are correct Taekwondo shoes rather than some knock-off/style-alikes that are not suitable) but not regular trainers or shoes. If you wear Taekwondo shoes you should wear white sports socks. Shoes must also be removed for sparring or target pad kicking and it's recommended to train without them when preparing for dan rank tests as shoes must not be worn for the test.
If you wish, you may wear a plain white T-shirt underneath your dobok in class, but again, this must not be worn for dan rank tests.
Long hair should be tied back and nails should be kept neatly trimmed.