The Driglam Namzha (Tibetan: སྒྲིག་ལམ་རྣམ་གཞག་, Wylie: sgrig lam rnam gzhag) is the official behaviour and dress code of Bhutan. It governs how citizens should dress in public and how they should behave in formal settings. It also regulates a number of cultural assets such as art and architecture. In English, driglam means "order, discipline, custom, rules, regimen" and namzha means "system", though the term may be styled "The Rules for Disciplined Behaviour".
The Driglam Namzha traces its roots directly back to the 17th-century pronouncements of Ngawang Namgyal, the first Zhabdrung Rinpoche, a Tibetan lama and military leader who sought to unify Bhutan not only politically but also culturally. He established guidelines for dzong architecture, the characteristic monastery-fortresses of Bhutan. He also established many of the traditions of the tshechu "district festival" such as the Cham dance. The guidelines were intentionally codified to encourage the emergence of a distinctively-Bhutanese identity.
In 1989, the government elevated the status of the dress code from recommended to mandatory. All citizens were then required to observe the dress code in public during business hours. The decree was resented by Lhotshampas in the southern lowlands, who complained about being forced to wear the clothing of the Ngalop people.
Under the Driglam Namzha, men wear a heavy knee-length robe tied with a belt, called a gho, which is folded in such a way to form a pocket in front of the stomach. Women wear colourful blouses called wonju over which they fold and clasp a large rectangular cloth called a kira, thereby creating an ankle-length dress. A short silk jacket or toego may be worn over the kira. Everyday gho and kira are cotton or wool according to the season, patterned in simple checks and stripes in earth tones. For special occasions and festivals, colourfully-patterned silk kira and, more rarely, gho, may be worn.
Additional rules apply when visiting a dzong or a temple, and when appearing before a high-level official. A white, raw silk sash with fringes called a kabney is worn by commoner men from left shoulder to opposite hip, with other colours reserved for officials and monks. Women wear a rachu, a narrow embroidered cloth draped over the left shoulder.
The Driglam Namzha codifies the traditional rules for the construction of the sacred fortresses known as dzongs. No plans are drawn up nor are nails allowed in their construction. Under the direction of an inspired lama, citizens build dzongs as part of their tax obligation to the state. As recently as 1998, by decree, all buildings must be constructed with multi-coloured wood frontages, small arched windows and sloping roofs.