Русско-англо-русский юридический словарь

Communications between parties that form part of a genuine attempt to resolve a dispute, and which are expressed to be, or are by implication, made ‘without prejudice’, will be protected by without prejudice privilege. This means that they are inadmissible in court and cannot be made the subject of a disclosure order in any proceedings (subject to certain exceptions). (LexisNexis)

Confidential interactions (both written and verbal) between parties that are making genuine attempts to resolve a dispute are often marked "without prejudice" (WP). This is effectively shorthand for saying: 'whilst I am trying to reach a settlement with you, I'm not admitting any part of the case or conceding or waiving any arguments or rights - so, my offers to achieve a commercial deal are without prejudice to my primary position that I'm right and you're wrong'.

In this scenario, correspondence and discussions are confidential and cannot be shown to the court or any other party, unless all parties to the communication have agreed to this (or one of the exceptions - as to which see below - applies). (Gowling WLG)