This digest in Spanish examines schools' dress-code policies and discusses the legal considerations and research findings about the effects of such changes. Most revisions to dress codes involve the use of uniforms, typically as a way to curb school violence and create a positive learning environment. A recent survey of secondary school principals found that 70 percent of principals believe that mandated uniforms would reduce discipline problems. However, people who oppose uniforms caution against unnecessary routinization, authoritarianism, and infringement of the freedom of expression. Opponents also claim that the lack of conclusive evidence whether uniforms have a positive impact should give uniform proponents pause. Research on the effects of uniforms has been mixed because most studies rely on informal observations. As far as the legality of such codes is concerned, legal rulings have been ambiguous, though federal courts consistently uphold school districts' rights to establish regulations for the routine operation of schools. However, the courts want to know how the policy affects education, and school administrators must realize that policies are more likely to succeed when parents are involved from the beginning. Also, having an "opt-out" provision can protect schools from legal challenges. Possible alternatives to uniforms include teaching conflict-resolution skills and increased security. (Contains 10 references.) (RJM)