Prefer (verb), and preferment (noun), describe the prosecution formally bringing a criminal allegation before a court, especially by presenting an indictment so a case may proceed to trial. The expression is largely historical and descriptive rather than a defined statutory term, but it appears in case law and court rules; its effect is governed by criminal procedure legislation and practice directions.
England and Wales: to prefer an indictment is to lodge and sign the indictment in the Crown Court. The phrase survives in contexts such as a voluntary bill of indictment. Outside indictable proceedings, modern practice speaks of charging (at the police station) or issuing a written charge and requisition (which replaced laying an information).
Northern Ireland: usage is broadly similar to England and Wales; the term is understood as presenting an indictment to commence Crown Court proceedings.
Scotland: prefer/preferment is not standard terminology. The Crown “libels” charges on a complaint or indictment, prepared by the Procurator Fiscal or Advocate Depute.
Ireland: older usage recognises preferring an indictment; modern practice refers to charging and the presentation of an indictment in the Circuit or Central Criminal Court following return for trial.
Preferment is thus the act of preferring a charge or indictment.