Section 1-207 of the UCC allows a party to issue a reserve of rightsA declaration that is intentionally retained all or certain legal rights to warn others of these rights. during the execution of a contract. This section raises a difficult question when a debtor makes a full payment cheque to pay a disputed debt. As mentioned in this chapter, the creditor cannot cash an amount beyond the cheque, since under general law, the acceptance of a full payment check for the payment of a disputed debt is an agreement and a satisfaction. What if, when recovering the cheque, the creditor reserves the right (in accordance with section 1-207) to take legal action beyond what the debtor offers? The courts are divided on this issue: with respect to the sale of UCC-regulated goods, some courts allow the creditor to sue the unpaid debt, although the cheque is labelled as “fully paid” and others do not. Nor does it take into account the promise to fulfill an existing obligation to the contractor.  This rule, however, has been considerably restricted by recent jurisprudence. The general rule is that if a creditor promises to pay a debt in return for a fraction of the payment upon payment of the agreed portion, does not represent a consideration for the commitment, as it is simply a partial performance of a contractual obligation already owed.   Therefore, the debtor remains responsible for the full amount, as he cannot compel the promisor to accept less. A prime example is Stilk v Myrick, where Stilk, a sailor, agreed with Myrick to sail his boat to the Baltic Sea and return for $5 a month.
During the journey, two men deserted. Myrick promised to raise stilk`s wages if Stilk agreed to stick to his contract in the face of desertions. Stilk agreed and upon his return to port, Myrick refused to pay him the extra wages. It was found that Myrick`s new promise was unworkable, for Stilk`s consideration to fulfill a duty he already owed under contract to Myrick was not a good idea of Myrick`s promise to increase his wages.  The Court of Appeal in Re Selectmove Ltd found that the practical doctrine of benefits arising from Williams/Roffey could not be used as an additional departure from the rule. In this case, it was found that teaching only applies if the original promise was a promise to pay more and not to pay less. The Court of Appeal in Re Selectmove was unable to distinguish Foakes/Beer (a decision of the House of Lords)  to apply Williams/Roffey (a decision of the Court of Appeal).  It remains to be seen whether the House of Lords would decide otherwise. In any event, the just principle of the Estoppel change of sola can give discharge to the debtor.  The restoration allows, in certain circumstances, the application of contracts relating to previous considerations. It provides in section 86, “Promise for Benefit Received”: the idea is a concept of English common law in contract law and a necessity for simple contracts (but not for special contracts through fault). The concept of consideration has been taken up by other common law legal systems, including the United States.
A treaty in its most basic definition is nothing more than a legally enforceable promise. A promise cannot be based on a reflection that was said, made or given before the promise. Something that will be said later will not be considered a quid pro quo. For example, if X promises to reward Y for an act that Y has already accomplished, then the execution of that act is a good reflection, because the promise to be rewarded for it is a past reflection and therefore not a good reflection.