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Last update: February 15, 2024

Analytical Guide to the Work of the International Law Commission

Subsequent agreements and subsequent practice in relation to interpretation of treaties*

*At its sixty-fourth session, in 2012, the Commission decided to change, in 2013, the format of the work on this topic and its title from "Treaties over time" to "Subsequent agreements and subsequent practice in relation to interpretation of treaties".

See also: Summary | Texts and Instruments

Mandate

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

None

Reports of the Working Group or Sub-Committee

None

Reports of the Special Rapporteur

  • Introduction and previous work of the Commission. Discussion of the scope, aim and possible outcome of the work. Consideration of the general rule and means of treaty interpretation; subsequent agreements and subsequent practice as means of interpretation; the definition of subsequent agreement and subsequent practice as means of treaty interpretation; and the attribution of treaty-related practice to a State. Discussion of the future programme of work.
    • First report of the Special Rapporteur, Mr. Georg Nolte (65th session of the ILC (2013))
  • The identification of subsequent agreement s and subsequent practice. Possible effects of subsequent agreements and subsequent practice in the interpretation of treaties. The form and value of subsequent practice under article 31 (3) (b) (IV). The conditions for an “agreem ent” of the parties regarding the interpretation of a treaty under article 31 (3) (V). Decisions adopted within the framework of Conferences of State Parties (VI). The possible scope for interpretation by subsequent agreements and subsequent practice (VII).
    • Second report of the Special Rapporteur, Mr. Georg Nolte (66th session of the ILC (2014))
  • Role of subsequent agreements and subsequent practice in relation to the interpretation of constituent instruments of international organizations. Proposal for draft conclusion 11.
    • Third report of the Special Rapporteur, Mr. Georg Nolte (67th session of the ILC (2015))
  • Legal significance, for the purpose of interpretation and as forms of practice under a treaty, of pronouncements of expert bodies and of decisions of domestic courts. Proposed draft conclusions 12 and 13. Structure and scope of the draft conclusions. Revision of draft conclusion 4 (3). Future programme of work.
    • Fourth report of the Special Rapporteur, Mr. Georg Nolte (68th session of the ILC (2016))
  • Summary and assessment of general comments and observations on the topic (chap. II); consideration of specific comments and observations regarding individual draft conclusions, followed by a recommendation of the Special Rapporteur for each draft conclusion (chap. III); recommendation of the Special Rapporteur regarding the final form of the draft conclusions (chap. IV); and the text of the draft conclusions adopted on first reading in 2016, with the changes recommended by the Special Rapporteur (annex).
    • Fifth report of the Special Rapporteur, Mr. Georg Nolte (70th session of the ILC (2018))

Reports of the Drafting Committee

  • 65th session of the International Law Commission (2013)
    • Text of draft conclusions 1–5 provisionally adopted by the Drafting Committee at the sixty-fifth session of the International Law Commission
    • Statement of the Chair of the Drafting Committee
  • 66th session of the International Law Commission (2014)
    • Texts and titles of draft conclusions 6 to 10 provisionally adopted by the Drafting Committee on 27 and 28 May and on 2 and 3 June 2014
    • Statement of the Chair of the Drafting Committee
  • 67th session of the International Law Commission (2015)
    • Text and title of draft conclusion 11 provisionally adopted by the Drafting Committee on 4 June 2015
    • Statement of the Chair of the Drafting Committee
  • 68th session of the International Law Commission (2016)
    • Text of the draft conclusions provisionally adopted by the Drafting Committee on first reading
    • Statement of the Chair of the Drafting Committee
  • 70th session of the International Law Commission (2018)
    • Text of the draft conclusions adopted by the Drafting Committee on second reading
    • Statement of the Chair of the Drafting Committee

Comments by Governments

 
 

Other

None

Reports of the International Law Commission

  • Report of the International Law Commission on the work of its sixtieth session, 5 May to 6 June and 7 July to 8 August 2008
    • The Working Group on the Long-term Programme of Work recommended the inclusion of the topic in the long-term programme of work on the basis of a revised and updated proposal by Mr. G. Nolte (annexed to the ILC Report).
    • The inclusion of the topics in the programme of work of the Commission was proposed and the establishment, at the sixty-first session of the Commission, of a study group on the topic was recommended.
    • The Commission endorsed the recommendation for the inclusion of the topic on the long-term programme of work.
  • ILC Report, A/63/10, 2008, chap. XII(A)(4), paras. 351–352
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/606 and Add.1)
  • Report of the International Law Commission on the work of its sixty-first session, 4 May to 5 June and 6 July to 7 August 2009
    • At its 3012th meeting, on 29 May 2009, the Commission established a Study Group on Treaties over Time, chaired by Mr. Georg Nolte. At its 3029th meeting, on 31 July 2009, the Commission took note of the oral report of the Chair of the Study Group on Treaties over time.
    • Discussion in Plenary: 3029th meeting, on 31 July 2009.
  • ILC Report, A/64/10, 2009, chap. XII, paras. 217–226
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/620 and Add.1)
  • Report of the International Law Commission on the work of its sixty-second session, 3 May to 4 June and 5 July to 6 August 2010
    • The Study Group on Treaties over time was reconstituted under the Chairship of Mr. Georg Nolte. At its 3071st meeting, on 30 July 2010, the Commission took note of the oral report of the Chair of the Study Group on Treaties over time and approved the recommendation of the Study Group that a request for information be included in Chapter III of the Commission’s report and also brought to the attention of States by the Secretariat.
    • Discussion in Plenary: 3071st meeting, on 30 July 2010.
  • ILC Report, A/65/10, 2010, chap. X, paras. 344–354
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/638)
  • Report of the International Law Commission on the work of its sixty-third session, 26 April to 3 June and 4 July to 12 August 2011
    • The Study Group on Treaties over time was reconstituted under the Chairship of Mr. Georg Nolte. At its 3119th meeting, the Commission took note of the oral report of the Chair of the Study Group on Treaties over time and approved the recommendation of the Study Group that the request for information included in Chapter III of the report of the Commission on the work of its sixty-second session (2010) be reiterated in Chapter III of the Commission’s report on its work at the current session.
    • Discussion in Plenary: 3119th meeting, on 8 August 2011.
  • ILC Report, A/66/10, 2011, chap. XI, paras. 333–344
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/650 and Add.1)
  • 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 the 2012 session, the Study Group on Treaties over time was reconstituted again under the Chairship of Mr. Georg Nolte. The Study Group held eight meetings, on 9, 10, 15, 16 and 24 May, and on 19, 25 and 26 July 2012.
    • At the 3135th meeting of the Commission, on 29 May 2012, the Chair of the Study Group presented a first oral report to the Commission on those aspects of the work undertaken by the Study Group at its five meetings from 9 to 24 May which were related to the format and the modalities of the Commission’s future work on this topic. In his report, the Chair indicated, inter alia, that the Study Group recommended that the Commission change the format of the work on this topic and appoint a Special Rapporteur.
    • At its 3136th meeting, on 31 May 2012, the Commission decided (a) to change, with effect from its sixty-fifth session (2013), the format of the work on the topic as suggested by the Study Group; and (b) to appoint Mr. Georg Nolte as Special Rapporteur for the topic “Subsequent agreements and subsequent practice in relation to the interpretation of treaties”.
    • On 30 July 2012, the Chair of the Study Group presented to the Commission a second oral report on the work done by the Study Group. The Commission took note of that oral report at its 3151st meeting on 30 July 2012
    • Discussion in Plenary: 3135th, 3136th meetings (29 and May 2012), 3151st (27 July 2012)
  • ILC Report, A/67/10, 2012, chap. X, paras. 222–240
  • 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.4/660), in which the Special Rapporteur, after addressing the scope, aim and possible outcome of the work on this topic (section II), considered the general rule and means of treaty interpretation (section III); subsequent agreements and subsequent practice as means of interpretation (section IV); the definition of subsequent agreement and subsequent practice as means of treaty interpretation (section V); and attribution of a treaty related practice to a State (section VI). The report also contained some indications as to the future programme of work (section VII). The Special Rapporteur proposed a draft conclusion corresponding with each of the four issues addressed in sections III to VI.
    • At its 3163rd meeting, on 14 May 2013, the Commission referred draft conclusions 1 to 4, as contained in the Special Rapporteur’s first report, to the Drafting Committee.
    • At its 3172nd meetings, on 31 May 2013, the Commission considered the report of the Drafting Committee and provisionally adopted five draft conclusions.
    • At its 3191st to 3193rd meetings, on 5 and 6 August 2013, the Commission adopted the commentaries to the draft conclusions provisionally adopted at the current session.
    • Discussion in Plenary: 3159th, 3160th, 3161st, 3162nd, 3163rd and 3172nd meetings, from 6 to 8 and on 10, 14 and 31 May 2013, respectively.
  • ILC Report, A/68/10, 2013, chap. IV, paras. 29–39
  • 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.4/671), which it considered at its 3205th to 3209th meetings, from 15 to 22 May 2014.
    • At its 3209th meeting, on 22 May 2014, the Commission referred draft conclusions 6 to 11, as contained in the second report of the Special Rapporteur, to the Drafting Committee. At its 3215th meeting, on 5 June 2014, the Commission considered the report of the Drafting Committee and provisionally adopted five draft conclusions. At its 3239th to 3240th meetings, on 6 August 2014, the Commission adopted the commentaries to the draft conclusions provisionally adopted at the session.
    • Discussion in Plenary: 3205th, 3206th, 3207th, 3208th and 3209th meetings (15 to 22 May 2014), 3215th meeting (5 June 2014), and 3239th and 3240th meetings (6 August 2014).
  • ILC Report, A/69/10, 2014, chap. VII, paras. 66–76
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/678)
  • 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.4/683), which it considered at its 3259th to 3262nd meetings, on 29 May, 2–4 June 2015.
    • At its 3262nd meeting, on 4 June 2015, the Commission referred draft conclusion 11, as contained in the third report of the Special Rapporteur, to the Drafting Committee. At its 3266th meeting, on 8 July 2015, the Commission considered the report of the Drafting Committee and provisionally adopted draft conclusion 11. At its 3284th to 3285th and 3288th meetings, on 4 and 6 August 2015, the Commission adopted the commentary to draft conclusion 11 as provisionally adopted at the session.
    • Discussion in Plenary: 3259th, 3260th, 3261st, and 3262nd meetings (29 May and 2–4 June 2015), 3266th meeting (8 July 2015), and 3284th, 3285th and 3288th meetings (4 and 6 August 2015).
  • ILC Report, A/70/10, 2015, chap. VIII, paras. 118–129
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/689)
  • 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.4/694). The Commission considered the report at its 3303rd to 3307th meetings, from 24 to 31 May 2016. At its 3307th meeting on 31 May 2016, the Commission decided to refer draft conclusions 1a and 12, as presented by the Special Rapporteur, to the Drafting Committee.
    • At its 3313th meeting, on 10 June 2016, the Commission considered the report of the Drafting Committee and adopted a set of 13 draft conclusions on subsequent agreements and subsequent practice in relation to the interpretation of treaties on first reading. At its 3335th to 3337th, 3340th and 3341st meetings, on 4, 5, 8 and 9 August 2016, the Commission adopted the commentaries to the draft conclusions on subsequent agreements and subsequent practice in relation to the interpretation of treaties.
    • At its 3341st meeting, on 9 August 2016, the Commission decided, in accordance with articles 16 to 21 of its statute, to transmit the draft conclusions, 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: 3303rd, 3304th, 3305th, 3306th, 3307th (24 to 31 May), 3313th (10 June), 3335th, 3336th, 3337th, 3340th and 3341st (4, 5, 8 and 9 August 2016) meetings.
  • ILC Report, A/71/10, 2016, chap. VI, paras. 64–76
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/703)
  • ILC Report, A/73/10, 2018, chap. IV, paras. 39–52
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/724)

General Assembly Action

  • Resolution 63/123 of 11 December 2008
    • Took note of 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.4/606 and Add.1)
  • Resolution 71/140 of 13 December 2016
    • Noted, inter alia, the completion of the first reading of the draft conclusions on subsequent agreements and subsequent practice in relation to the interpretation of treaties with the adoption of an entire set of draft conclusions on the topic.
    • Drew the attentionof Governments to the importance for the International Law Commission of having their comments and observations by 1 January 2018 on the draft conclusions.
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/703)

Final Outcome

International Law Commission (70th session, 2018)

  • The Commission adopted the  draft conclusions on subsequent agreements and subsequent practice in relation to the interpretation of treaties, on second reading, with commentaries.
  • The Commission decided, in accordance with article 23 of its statute, to recommend that the General Assembly take note in a resolution of the draft conclusions on subsequent agreements and subsequent practice in relation to the interpretation of treaties, annex the draft conclusions to the resolution, and ensure their widest dissemination; and commend the draft conclusions, together with the commentaries thereto, to the attention of States and all who may be called upon to interpret treaties.
 

General Assembly

  • Resolution 73/202 of 20 December 2018
    • Welcomed the conclusion of the work of the International Law Commission on subsequent agreements and subsequent practice in relation to the interpretation of treaties, and its adoption of the draft conclusions and commentaries thereto;
    • Took note of the statements in the Sixth Committee on the subject, including those made at the seventy-third session of the General Assembly, after the International Law Commission had completed its consideration of this topic in accordance with its statute;
    • Also took note of the conclusions on subsequent agreements and subsequent practice in relation to the interpretation of treaties, the text of which was annexed to the resolution, with the commentaries thereto, brought them to the attention of States and all who may be called upon to interpret treaties, and encouraged their widest possible dissemination.
  • See the website of the Sixth Committee of the General Assembly and the topical summary of debate in the Sixth Committee (A/CN.4/724)