The issuing of Letters of Marque and Reprisal started initially as a method of legal redress, the reprisal part hints at this. However this was so widely abused that it became little more than piracy. The diplomatic difficulties caused lead states to agree on certain basic principles for the regulation of privateering.

Letters of marque were no longer used as a means of settling a private wrong and now were only issued at commencement of sate sanctioned hostilities that is following a declaration of war. That captured enemy vessels had to be judged before an Admiralty court and neutrals rights had to be respected. Infringement of these regulations could lead to the forfeiture of the bond fro good behaviour or in some case the impressment of the offending crew.

The works following show how complex the rules were and how carful the privateering commander had to be.

Henry J. Bourguignon, Sir William Scott, Lord Stowell: Judge of the High Court of Admiralty, 1798-1828 ( Cambridge University press, 1989

This gives and excellent academic survey of how prize law functioned in this period.

Richard Hill, The Prizes of war: the naval prize system in the Napoleonic Wars 1793 -1815 (UK:Sutton publishing, 1998)

Donald A. Petrie The Prize Game: lawful looting on the High Seas in the days for fighting sail (Maryland: Naval Institute press, 1999)