The American Bar Association has published professional standards that serve as models of the law governing lawyers since the adoption of the Canons of Professional Ethics in 1908. The latest version of these standards is the Model Rules of Professional Conduct, first adopted in 1983 and amended a number of times since then. The Model Rules replaced the Model Code of Professional Responsibility, which was adopted in 1969.
The Model Rules are not binding on anyone, but serve as a model for adoption by states. Codes or rules of professional conduct for lawyers function similarly to statutes. However, most are not adopted by the legislature but, instead, by state bar associations or the highest court of the jurisdiction