If the contractual conditions are uncertain or incomplete, the parties cannot have reached an agreement in the eyes of the law. [58] An agreement does not constitute a contract and failure to agree on key issues that may include issues such as price or safety can lead to the failure of the entire contract. However, a court will endeavour, to the extent possible, to permit commercial agreements by interpreting an appropriate design of the contract. [59] In New South Wales, even if a contract is uncertain or incomplete, the contract may be binding on the parties if there is a sufficiently secure and comprehensive clause requiring the parties to submit to arbitration, negotiation or mediation. [60] To reach an agreement, it is sufficient for the parties to reach a common understanding of their relative rights and obligations, often referred to as „meetings of minds.” The requirements for concluding the contract are more precise and relatively strict. A contract must contain the following essential elements: conversely, domestic and social agreements such as those concluded between children and parents are generally inapplicable on the basis of public policy. For example, in the English case Balfour v. Balfour, a husband, agreed to give his wife £30 a month when he was not at home, but the court refused to enforce the agreement when the husband stopped paying. In contrast, in Merritt vs. Merritt, the Tribunal enforced an agreement between an alienated couple because the circumstances suggested that their agreement should have legal consequences. .