The period of time to file a sales contract is increased to six months from the date of its signing and it is possible to file the sales contract by decision after the expiry of this period if it benefits the buyer. Other agreements may also be filed, such as exchange or repurchase contracts, and any clause in a purchase or transfer agreement prohibiting its deposit is deemed to be cancelled. The main aspect of the litigation to be the subject of legal proceedings was the resulting effect that the prohibited implementation of the non-sale clause would have on the letter of surrender, in light of the contractual obligations that BP and NBAD would have to each other. Upon signing the purchase or transfer contract, the buyer must continue the stamp of the contract within thirty (30) days from the date of signing. Stamp duty is calculated as follows: One of the new features of the new legal references is the right of buyers and other parties not to have filed their contracts within six months of 29.7.2011, regardless of the signing period. This right is granted to any purchaser or other party in spite of any pending litigation before the Court concerning such a sales contract or agreement. The new law, which provides for the filing of transfers or other agreements to the land registry, the consequences, the obligations of the seller and the specific benefit recently adopted, was published in the Official Journal on 29.4.2011, provided that it will come into force after three months after its publication. A recent case under review that has helped to further clarify the applicable legal principles for contracts is that of the National Bank of Abu Dhabi PJSG/BP Oil Limited (2016) EWHC 2892, the facts of which are outlined below: BP has entered into an agreement with a Moroccan refining company, the Moroccan Anonymous Society of Refining Industry (SAMIR). to which it supplied Russian crude oil or the Urals. This was based on the terms and conditions of BP`s contract, which included the “limitation of assignment” clause: while a trust`s statement on revenue is easily understandable, a more problematic question arises as to whether the original lender can also have confidence in the usefulness of the contract. This was raised in Don King, where Lightman J felt that this was not a problem, since the attributions and trusts were essentially different legal concepts.