In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

A plaintiff is a person who starts a lawsuit in court .
A plaintiff ( Π in legal shorthand ) is the party who initiates a lawsuit ( also known as an " action " ) before a court .

The Convention also says that any toxic chemical is a chemical weapon unless it is used for legal reasons .
Under this Convention , any toxic chemical , regardless of its origin , is considered a chemical weapon unless it is used for purposes that are not prohibited ( an important legal definition known as the General Purpose Criterion ) .

A collusion is a secret agreement between two or more people or groups , usually to create unlawful advantages over other groups .

A secret agreement between two or more parties to limit open competition by deceiving , misleading , or defrauding others of their legal rights , or to obtain an objective forbidden by law typically by defrauding or gaining an unfair market advantage is an example of collusion .

