It is a form of defamation and can be a form of an ad hominem (to the person) argument.
Child abuse is the physical or psychological/emotional mistreatment of children.
Abuse of authority is separated from abuse of power in that the act is originally condoned, but is extended beyond that initially conceived and is in not all cases An abuse of discretion is a failure to take into proper consideration, the facts and laws relating to a particular matter; an arbitrary or unreasonable departure from precedent and settled judicial custom.
Abuse of information typically involves a breach of confidence or plagiarism, or extending the confidence of information beyond those authorised.
Discriminatory laws such as redlining have existed in many countries.