Task: Question Answering
Input (English): Passage: Patel and Menon backed up their diplomatic efforts by producing treaties that were designed to be attractive to rulers of princely states. Two key documents were produced. The first was the Standstill Agreement, which confirmed the continuance of the pre-existing agreements and administrative practices. The second was the Instrument of Accession, by which the ruler of the princely state in question agreed to the accession of his kingdom to independent India, granting the latter control over specified subject matters. The nature of the subject matters varied depending on the acceding state. The states which had internal autonomy under the British signed an Instrument of Accession which only ceded three subjects to the government of India—defence, external affairs, and communications, each defined in accordance with List 1 to Schedule VII of the Government of India Act 1935. Rulers of states which were in effect estates or talukas, where substantial administrative powers were exercised by the Crown, signed a different Instrument of Accession, which vested all residuary powers and jurisdiction in the Government of India. Rulers of states which had an intermediate status signed a third type of Instrument, which preserved the degree of power they had under the British.The Instruments of Accession implemented a number of other safeguards. Clause 7 provided that the princes would not be bound to the Indian constitution as and when it was drafted. Clause 8 guaranteed their autonomy in all areas that were not ceded to the Government of India. This was supplemented by a number of promises. Rulers who agreed to accede would receive guarantees that their extra-territorial rights, such as immunity from prosecution in Indian courts and exemption from customs duty, would be protected, that they would be allowed to democratise slowly, that none of the eighteen major states would be forced to merge, and that they would remain eligible for British honours and decorations. In discussions, Lord Mountbatten reinforced the statements of Patel and Menon by emphasising that the documents gave the princes all the "practical independence" they needed. Mountbatten, Patel and Menon also sought to give princes the impression that if they did not accept the terms put to them then, they might subsequently need to accede on substantially less favourable terms. The Standstill Agreement was also used as a negotiating tool, as the States Department categorically ruled out signing a Standstill Agreement with princely states that did not sign an Instrument of Accession. 
Question: What are the full names of the two key documents that were produced by Patel and Menon in their diplomatic appeals?
Output (English): Standstill Agreement.