This is called consent or waiver, which means that the parties agree to continue a contract despite the negligence of a minor delay. They must also promise another asset to ensure that the endorsement has consideration and is therefore a valid contract. Talk to a lawyer if you are not sure that consideration is a prerequisite, as this depends on both national and contract law. The following is the addendum developed for the Harvard FAS faculty in collaboration with the Harvard FAS Open Access Policy of February 12, 2008. All terms of the Publication Agreement, including all grants, agreements, assurances and warranties, are subject to a non-exclusive license previously granted by the author to Harvard University.