to the treaty bodies. There may be many reasons why States fail to report, ranging from war and civil strife to limited resources. Technical assistance is available from OHCHR to assist States in meeting their reporting obligations. The treaty bodies have also adopted procedures to ensure that the implementation of the treaties by non-reporting States parties is reviewed, if the latter have not responded to a treaty body’s requests for information. In particular, committees are prepared to consider the situation in a country in the absence of a report. Information on the reporting status of the State parties to each treaty is available from the treaty body database on the OHCHR website or in HRI/ GEN/4, which is updated annually. The website also provides information on the technical assistance available to State parties. Optional protocol An international instrument which is linked to a principal instrument and imposes additional legal obligations on States that choose to accept them. Optional protocols may be drafted at the same time as the main treaty or after the main treaty has entered into force. Optional protocols to the human rights treaties have been adopted for a number of reasons: to allow State parties to sign up to additional obligations relating to international monitoring of implementation (first Optional Protocol to the International Covenant on Civil and Political Rights, optional protocols to the Convention on the Elimination of All Forms of Discrimination against Women, to the Convention against Torture, to the Convention on the Rights of Persons with Disabilities, and to the International Covenant on Economic, Social and Cultural Rights, and the Optional Protocol to the Convention on the Rights of the Child on a communications procedure); to allow States to assume additional obligations that were not in the main treaty (Second Optional Protocol to the International Covenant on Civil and Political Rights); or to address particular problems in more detail (the first two optional protocols to the Convention on the Rights of the Child). Periodicity The timetable for the submission of initial and periodic reports by State parties to the treaty bodies is set out in each treaty or decided by the individual committees in accordance with the terms of the treaty. An initial report is required within a fixed period after the treaty enters into force for the State concerned; periodic reports are then required at regular intervals. The periodicity differs from treaty to treaty. (See table in chap. II, sect. C.) 53