There are several reasons for an institution or organization to have a dress code. One is to promote unity and cohesion, since people who dress alike tend to subconsciously bond together; this is one of the reasons for various military and paramilitary groups to have a standard uniform. Another reason is to project a certain attitude or culture, such as business casual or professional; this is why many legal firms and offices require business professional or business casual dress. A third reason is to discourage the formation of subgroups – this is often the reason for school uniforms, as administrators try to keep cliques and other in-groups from forming based upon clothing worn. A fourth reason would be safety, particularly in industry and manufacturing – you need to wear close-fitting clothes (no long flowing sleeves or ties) around machinery to reduce your risk of being pulled into the machine and killed.