Universal design is the design of buildings, products, or environments to make them accessible to all people, regardless of age, disability, or other factors. It emerged as a rights-based, anti-discrimination measure, which seeks to create design for all abilities. It addresses common barriers to participation by creating things that can be used by the maximum number of people possible. "When disabling mechanisms are to be replaced with mechanisms for inclusion, different kinds of knowledge are relevant for different purposes. As a practical strategy for inclusion, Universal Design involves dilemmas and often difficult priorities." Curb cuts or sidewalk ramps, which are essential for people in wheelchairs but also used by all, are a common example of universal design.