In general, writers have made Marxist and feminist interpretations of the treaty. attempts to understand the purpose and nature of the treaty as a phenomenon of global understanding, in particular, the relational theory of contracts, originally developed by American experts Ian Roderick Macneil and Stewart Macaulay, which was based at least in part on the contract theory of the American scientist Lon L. Fuller, while American scientists were at the forefront of the development of the economic theories of contracts focused on transaction costs and the so-called “effective violation”. However, in certain circumstances, certain commitments that are not considered contracts may be applied to a limited extent. If one party relied on the other party`s assurances/promises to its detriment, the court may apply a just doctrine of Promissory Estoppel to compensate the non-injurious party to compensate the party for the amount it received from the appropriate appeal of the party to the agreement. Some agreements may be legally applicable, others may not. A tacit and tacit contract, also known as the “party contract,” which can be either a tacit contract or an unspoken contract, can also be legally binding. In the case of unspoken contracts, these are real contracts for which the parties enjoy the “benefit of the good deal”.  However, legally underlying contracts are also called quasi-contracts and the remedy is quantum, the fair value of the goods or services provided. An agreement on an illegal act is therefore null and for granted and cannot be enforced in court. It should also be noted that there is a distinction between non-legal and illegal agreements. Any illegal agreement is illegal, but not all non-legal agreements must necessarily be illegal.
A contract is often proven in writing or by deed, the general rule is that a person who signs a contractual document is bound by the terms of that document, this rule is referred to as the rule of L`Estrange/Graucob.  This rule is approved by the High Court of Australia in Toll (FGCT) Pty Ltd/Alphapharm Pty Ltd.  However, a valid contract may be entered into orally (with a few exceptions) or even by conduct.  Corrective measures in the event of breach of contract include damages (monetary compensation for loss)  and, only in the case of a serious offence, refusal (i.e. refusal).