To treat one particular group of people less favourably than others because of their race, colour, nationality, or ethnic or national origin. The law in Britain recognises two kinds of discrimination: direct and indirect. Direct discrimination occurs when a 'protected characteristic' such as race, colour, nationality, or ethnic or national origin is used as an explicit reason for discriminating. Indirect discrimination occurs when there are provisions, criteria or practices operating, which have the effect of discriminating against certain groups of people, by putting them at a disadvantage compared with others, and which cannot be justified as proportionate. This may happen in subtle ways. For example, school or staff uniform dress codes may breach equality law if they would offend religious or customary mores of particular racial groups and are not necessary for the job. Staff at a shop in Blackburn had to wear a uniform skirt, but an Asian woman worker refused for religious reasons. A tribunal found the shop guilty of indirect discrimination, because a large number of Asian women would not be able to comply with the rule.