Advocacy is an umbrella term for organized activism related to a particular set of issues.
Unlike much propaganda, advocacy is expected to be non-deceptive and in good faith. Typical examples of advocacy in the computing world include operating system advocacy and open source advocacy.
Issue advocacy is any speech relating to issues and the policy positions taken by political candidates and elected officials. It can be as simple as a single statement or it can be as involved as a multimillion dollar campaign of broadcast and print advertisements that spreads the same message. Any group or individual can engage in issue advocacy. A message stops being issue advocacy if it expressly endorses the election or defeat of a candidate. (See also single-issue politics.)
List of advocacy groups