There are more than hundred different styles in 'Arabic calligraphy'. Among them are the classical styles Sulus, Naskh, Diwani,Ruq’ah ,Kufi,
Muhaqqaq, Raihani, Tawqi, etc., as well as the Persian styles Nastaliq, Shekasta and its variants Moalla, Kerishma,Sunbuli etc all those scripts have specific rules and terms of writing. Competitors can write in whatever style they have practiced, or in their own freestyle of their own hands.