Definition - What does Ex Rel. mean?
Ex rel. (ex relatione) is a Latin term that means "upon being related."
This term is commonly used to label cases where a trial is ensuing "ex rel.," or upon being related to information provided by another source.
Many whistleblower lawsuits are ex rel. suits because the information comes from the whistleblower.
Justipedia explains Ex Rel.
Many lawsuits occur because one party discovers information about another party and wants to pursue justice against that party. However, that is not always the case.
Sometimes, one party discovers and brings to light information about another party, and then a third party brings the second party to trial as a result of the first party's information. When such an event happens, the term ex rel. is often used to describe the ensuing case and trial.