California’s Division of Labor Standards Enforcement (DLSE), which is also known as the Labor Commissioner’s Office, is a government agency tasked with enforcing California’s Labor Code and wage and hour laws. The DLSE publishes agency advice letters, called opinion letters, which provide guidance to the public and agency’s staff. Also, the interpretations of wage and hour laws in opinion letters are entitled to great weight in determining the outcome of disputes between employers and employees, even though the opinion letters themselves are not laws that are controlling on courts.
One interesting aspect of opinion letters is that the longer an advice letter has been around, the more they become like undisputed laws because legislators can be presumed to have intentionally chosen not to change a longstanding interpretation of law after enough time passes.