International Law Commission International Law Commission

Last update: September 23, 2016

Analytical Guide to the Work of the International Law Commission

Identification of customary international law*

*At its sixty-fifth session, in 2013, the Commission decided to change the title of the topic from "Formation and evidence of customary international law" to "Identification of customary international law".

See also: Summary | Texts and Instruments

Mandate

Studies undertaken by the Secretariat and Reports of the Secretary-General

  • 65th session of the International Law Commission (2013)
    • Memorandum prepared by the Secretariat
  • 68th session of the International Law Commission (2016)
    • Memorandum prepared by the Secretariat

Reports of the Working Group or Sub-Committee

None

Reports of the Special Rapporteur

  • Introduction and summary of previous work of the Commission. Discussion on the scope of the topic (including whether jus cogens should be covered), and possible outcomes; consideration of issues concerning customary international law as a source of law, including Article 38, para. 1 (b) of the Statute of the International Court of Justice and terminology; description of the principal categories of materials on the processes of formation and evidence of customary international law (practice of States and other intergovernmental actors; case law of the International Court of Justice and other courts and tribunals; the work of other bodies; and writings); including a consideration of the various approaches suggested for, and the experience accumulated with regard to, the formation and evidence of rules of customary international law.
    • First report of the Special Rapporteur, Sir Michael Wood (65th session of the ILC (2013))
  • Consideration of the scope and outcome of the topic and of the use of terms. Discussion of the approach to the identification of rules of “general” customary international law, in particular the two constituent elements (“State practice”and “opinio juris”, respectively) and how to determine whether they are present. Proposals for 11 draft conclulsions. Discussion of the future programme of work.
    • Second report of the Special Rapporteur, Sir Michael Wood (66th session of the ILC (2014))
  • Completion of the set of draft conclusions proposed by the Special Rapporteur. Addresses matters not covered in the second report, and others to which it was agreed the Commission would return in 2015. Section II addresses further the relationship between the two constituent elements; section III encompasses a more detailed enquiry into inaction as practice and/or evidence of acceptance as law; section IV examines the role of treaties and resolutions adopted by international organizations and at international conferences; section V addresses judicial decisions and writings; section VI; returns to the issue of the practice of international organizations; sections VII and VIII examine two particular issues, namely, particular custom and the persistent objector; and section IX suggests the future programme of work on the topic.
    • Third report of the Special Rapporteur, Sir Michael Wood (67th session of the ILC (2015))
  • Responses to the main comments and suggestions made by States and others in relation to the 16 draft conclusions provisionally adopted by the Drafting Committee in 2014 and 2015. Proposals by the Special Rapporteur for minor modifications to the texts provisionally adopted by the Drafting Committee. Discussion of the ways and means to make the evidence of customary international law more readily available. Suggestions concerning the future programme of work on the topic.
    • Fourth report of the Special Rapporteur, Sir Michael Wood (68th session of the ILC (2016))

Reports of the Drafting Committee

 
  • 67th session of the International Law Commission (2015)
    • Text of draft conclusions 1 to 16 [15] provisionally adopted by the Drafting Committee at the sixty-sixth and sixty-seventh sessions
    • Statement of the Chairman of the Drafting Committee
  • 68th session of the International Law Commission (2016)
    • Text of the draft conclusions provisionally adopted by the Drafting Committee
    • Statement of the Chairman of the Drafting Committee

Comments by Governments

 
 
 

Other

  • 64th session of the International Law Commission (2012)
    • Note by Michael Wood, Special Rapporteur

Reports of the International Law Commission

  • Report of the International Law Commission on the work of its sixty-fourth session, 7 May to 1 June and 2 July to 3 August 2012
    • At its 3132nd meeting, on 22 May 2012, the Commission decided to include the topic “Formation and evidence of customary international law” in its programme of work and appointed Mr. Michael Wood as Special Rapporteur for the topic.
    • During the second part of the session, the Commission had before it a Note by the Special Rapporteur (A/CN.4/653). The Commission considered the Note at its 3148th, 3150th, 3151st and 3152nd meetings.
    • At its 3153rd meeting, on 30 July 2012, the Commission requested the Secretariat to prepare a memorandum identifying elements in the previous work of the Commission that could be particularly relevant to this topic.
    • Discussion in Plenary: 3132nd (22 May 2012), 3148th meetings, 3150th, 3151st, 3152nd and 3153rd meetings (24, 26, 27 and 30 July 2012)
  • ILC Report, A/67/10, 2012, chap. VIII, paras. 156–202
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/657)
  • Report of the International Law Commission on the work of its sixty-fifth session, 6 May to 7 June and 8 July to 9 August 2013
    • The Commission had before it the first report of the Special Rapporteur (A/CN.4/663), as well as a memorandum of the Secretariat on the topic (A/CN.4/659).
    • At its 3186th meeting, on 25 July 2013, the Commission decided to change the title of the topic to “Identification of customary international law”.
    • Discussion in Plenary: 3181st, 3182nd, 3183rd, 3184th, 3185th and 3186th meetings, from 17 to 25 July 2013, respectively.
  • ILC Report, A/68/10, 2013, chap. VII, paras. 63–107
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/666)
  • Report of the International Law Commission on the work of its sixty-sixth session, 5 May–6 June and 7 July–8 August 2014
    • The Commission had before it the second report of the Special Rapporteur (A/CN.4/672). At its 3227th meeting, on 18 July 2014, the Commission referred draft conclusions 1 to 11, as contained in the second report of the Special Rapporteur, to the Drafting Committee. At the 3242nd meeting of the Commission, on 7 August 2014, the Chairman of the Drafting Committee presented the interim report of the Drafting Committee on “Identification of customary international law”, containing the eight draft conclusions provisionally adopted by the Drafting Committee at the sixty-sixth session. The report, together with the draft conclusions, were presented for information only, and were made available on the Commission's website.
    • Discussion in Plenary: 3222nd, 3223rd, 3224th, 3225th, 3226th and 3227th meetings (11 to 18 July 2014), 3242nd and 3243rd meetings (7 and 8 August 2014).
  • ILC Report, A/69/10, 2014, chap. X, paras. 133–185
  • Report of the International Law Commission on the work of its sixty-seventh session, 4 May–5 June and 7 July–7 August 2015
    • The Commission had before it the third report of the Special Rapporteur (A/CN.4/682). The Commission considered the report at its 3250th to 3254th meetings, from 13 to 21 May 2015.
    • At its 3254th meeting, on 21 May 2015, the Commission referred the draft conclusions contained in the third report of the Special Rapporteur, to the Drafting Committee.
    • At the 3280th meeting of the Commission, on 29 July 2015, the Chairman of the Drafting Committee presented the report of the Drafting Committee on “Identification of customary international law”, containing draft conclusions 1 to 16 [15], provisionally adopted by the Drafting Committee at the sixty-sixth and sixty- seventh sessions (A/CN.4/L.869).
    • At its 3288th meeting, on 6 August 2015, the Commission took note of draft conclusions 1 to 16.
    • At its 3288th meeting, on 6 August 2015, the Commission requested the Secretariat to prepare a memorandum concerning the role of decisions of national courts in the case-law of international courts and tribunals of a universal character for the purpose of the determination of customary international law.
    • Discussion in Plenary: 3250th, 3251st, 3252nd, 3253rd and 3254th meetings (13 to 21 May 2015), 3280th meeting (29 July 2015) and 3288th meeting (8 August 2015).
  • ILC Report, A/70/10, 2015, chap. VI, paras. 55–107
  • Report of the International Law Commission on the work of its sixty-eighth session, 2 May–10 June and 4 July–12 August 2016
    • The Commission had before it the fourth report of the Special Rapporteur (A/CN.4/695), and an addendum to that report (A/CN.4/695/Add.1) providing a bibliography on the topic. In addition, the Commission had before it a memorandum by the Secretariat concerning the role of decisions of national courts in the case-law of international courts and tribunals of a universal character for the purpose of the determination of customary international law (A/CN.4/691).
    • The Commission considered the fourth report of the Special Rapporteur, as well as the memorandum by the Secretariat, at its 3301st to 3303rd meetings, from 19 to 24 May 2016. At its 3303rd meeting, on 24 May 2016, the Commission referred to the Drafting Committee the proposed amendments to the draft conclusions contained in the fourth report of the Special Rapporteur.
    • At its 3303rd meeting, on 24 May 2016, the Commission also requested the Secretariat to prepare a memorandum on ways and means for making the evidence of customary international law more readily available, which would survey the present state of the evidence of customary international law and make suggestions for its improvement.
    • The Commission considered and adopted the report of the Drafting Committee on draft conclusions 1 to 16 (A/CN.4/L.872) at its 3309th meeting, on 2 June 2016. It accordingly adopted a set of 16 draft conclusions on identification of customary international law on first reading.
    • At its 3338th to 3340th meetings, on 5 and 8 August 2016, the Commission adopted the commentaries to the draft conclusions on identification of customary international law.
    • At its 3340th meetings on 8 August 2016, the Commission decided, in accordance with articles 16 to 21 of its statute, to transmit the draft, through the Secretary-General, to Governments for comments and observations, with the request that such comments and observations be submitted to the Secretary-General by 1 January 2018.
    • Discussion in Plenary: 3291st (2 May) 3301st, 3302nd, 3303rd (19 to 24 May), 3309th (2 June 2016), 3338th, 3339th, and 3340th (5 and 8 August 2016) meetings.
  • ILC Report, A/71/10, 2016, chap. V, paras. 50–63

General Assembly Action

  • Resolution 67/92 of 14 December 2012
    • Noted with appreciation the decision of the International Law Commission to include the topic in its programme of work.
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/657)

Final Outcome

Work in progress