ITU-T Recommendations -- structure & approval
Document types by lifecycle stage
| Document type |
Meaning |
Approval |
| Recommendation |
Normative output of a study group |
TAP or AAP |
| Amendment |
Changes/additions to published Recommendation |
Same approval as the Recommendation |
| Corrigendum |
Corrections to published Recommendation |
Same approval as amendment |
| Erratum |
Publication/editorial error fix |
Published by TSB with Chairman concurrence (no SG approval) |
| Annex (integral) |
Material necessary for completeness |
Same approval as Recommendation |
| Appendix (non-integral) |
Supplementary, not essential |
Agreed by study group (not full approval) |
Recommendation clause structure
Per the Rules for presentation of ITU-T | ISO/IEC common text, a
Recommendation is organized as follows:
| Clause |
Element |
Content |
| (preliminary) |
Cover page, Contents, Foreword, Introduction |
Roman numeral pages |
| 1 |
Scope |
Defines subject and limits; no requirements |
| 2 |
Normative references |
Documents whose provisions are referenced normatively |
| 3 |
Definitions (optional) |
Terms defined for this Recommendation. Subdivided into 3.1 "Terms defined elsewhere" and 3.2 "Terms defined in this Recommendation" (if both are used). See term formatting below. |
| 4 |
Abbreviations (optional) |
All abbreviations used in the text |
| 5 |
Conventions (optional) |
Any particular notation used |
| 6+ |
Text |
Body of the Recommendation |
| Annex A+ |
Integral annexes |
Normative material (same approval as Recommendation) |
| Annex (continues) |
Non-integral annexes |
Informative/supplementary (SG agreement, not full approval) |
| (last, optional) |
Bibliography |
Informative references not cited normatively; heading style Appendix_No & title with page break before |
| (last) |
Index (optional) |
|
Canonical skeleton template
For new Recommendation drafting and for checking currently published Word
style definitions, use the local downloaded skeleton first:
assets/itu-t-recommendation-skeleton.docx
Upstream source URL (for refresh):
https://www.itu.int/en/ITU-T/studygroups/Documents/Doc-ITUT-Recs-Skelet.docx
Term formatting (clause 3)
Terms in clause 3 are formatted as pseudo-subclauses: they carry
subclause-style numbering (3.1.1, 3.1.2, ...) but are not real heading
paragraphs and do not appear in the table of contents.
Each term follows this pattern:
<bold>3.1.N\tTERM NAME</bold>: definition text
- The number prefix (
3.1.N) and term name are bold
- A tab separates the number from the term name
- The term name ends with a colon and space, followed by the definition
text (not bold)
- The paragraph uses
body-text style with a manually set tab stop at
1.5 cm (851 twips) — this tab stop is not part of the default
Normal style in the ITU-T template
This format applies to both 3.1 "Terms defined elsewhere" and
3.2 "Terms defined in this Recommendation".
Subdivision numbering
- Digits separated by periods: 1, 1.1, 1.1.1
- No trailing period after single number
- Do not create subclause 1.1 unless 1.2 also exists
Bibliography
The Bibliography is an optional, non-normative clause containing
informative references (sources not cited normatively in the body).
- Position: Always the last clause of the Recommendation, after all
integral and non-integral annexes (and before the Index if present).
- Heading: Formatted with style
Appendix_No & title (the same style
used for non-integral appendix headings). Write only the word
Bibliography — no number prefix.
- Page break: There must be a page break immediately before the
Bibliography heading. Apply it as
pageBreakBefore: true on the heading
paragraph, not as a separate break paragraph.
- Entries: Each entry uses style
References — the same style as
normative reference entries in clause 2. Format: [N]\t<citation text>
with a {SEQ Ref \* ARABIC} field and bookmark.
See itut-drafting for the concrete style-name mapping and officecli
commands.
Notes (from the Rules)
- Integrated in text: shall not contain requirements. Use "NOTE -- " for
single note, "NOTE 1 -- ", "NOTE 2 -- " for multiple.
- Notes to tables/figures: may contain requirements. Start with
"NOTE 1 -- ". Located within table frame or above figure title.
- Notes are indented from the main text margin.
Use of normative words
| Word |
Meaning |
| shall |
Mandatory requirement |
| shall not |
Prohibition |
| may |
Permission; indicates an action that is permitted but not required |
| need not |
Negative of "may" (avoid "may not") |
Figures and tables (from the Rules)
Figures
- Numbered with Arabic numerals, independent of clauses (e.g. Figure 1, Figure 2)
- Title below figure, centred: "Figure x -- title"
- Referenced as "see Figure 1" (uppercase "F")
Tables
- Numbered with Arabic numerals, independent of clauses (e.g. Table 1, Table 2)
- Title above table, centred: "Table x -- title"
- Columns framed, headings separated by horizontal line
- Spanning pages: "(continued)" / "Table x (concluded)"
ITU-T | ISO/IEC common text
When a Recommendation is jointly developed with ISO/IEC:
Terminology
- Common text: Identical text in both ITU-T Rec and ISO/IEC IS
- Identical Recommendations | International Standards: Same text
- Paired Recommendations | International Standards: Technically aligned but not identical ("twin text")
Self-reference
- In Scope/boilerplate: "this Recommendation | International Standard"
- Elsewhere: use a capitalized descriptive term (e.g. "this Specification")
Dual notation
External references use ITU-T first: "see Rec. ITU-T X.882 | ISO/IEC 13712-3"
Title
- Introductory element: "Information technology"
- Up to 3 elements, general to particular
- First letter of each element capitalized
References
- references/rules-recommendation-structure.md -- detailed extract from Rules for presentation
Cross-references
itut-basics -- ITU-T organization, roles, meeting procedures
itut-contributions -- contribution submission and TDocs
itut-drafting -- ITU-T contribution .docx template and formatting
itut-patents -- patent policy, IPR disclosure, licensing declarations
sdo-docx-formatting -- formatting rules (delegated)
1---2name: itut-recommendations3description: ITU-T Recommendation structure, approval processes, amendment/corrigendum procedures, and ITU-T | ISO/IEC common text conventions. Use when the agent needs to understand how ITU-T Recommendations are structured (clause order, element types, annex conventions), approved (TAP/AAP), amended, or how joint ITU-T/ISO/IEC texts work. Sources: Rec. ITU-T A.1 (09/2019) + Rules for presentation of ITU-T | ISO/IEC common text (2014).4---56# ITU-T Recommendations -- structure & approval78## Document types by lifecycle stage910| Document type | Meaning | Approval |11|---------------|---------|----------|12| **Recommendation** | Normative output of a study group | TAP or AAP |13| **Amendment** | Changes/additions to published Recommendation | Same approval as the Recommendation |14| **Corrigendum** | Corrections to published Recommendation | Same approval as amendment |15| **Erratum** | Publication/editorial error fix | Published by TSB with Chairman concurrence (no SG approval) |16| **Annex** (integral) | Material necessary for completeness | Same approval as Recommendation |17| **Appendix** (non-integral) | Supplementary, not essential | Agreed by study group (not full approval) |1819______________________________________________________________________2021## Recommendation clause structure2223Per the Rules for presentation of ITU-T | ISO/IEC common text, a24Recommendation is organized as follows:2526| Clause | Element | Content |27|--------|---------|---------|28| *(preliminary)* | Cover page, Contents, Foreword, Introduction | Roman numeral pages |29| 1 | **Scope** | Defines subject and limits; no requirements |30| 2 | **Normative references** | Documents whose provisions are referenced normatively |31| 3 | **Definitions** *(optional)* | Terms defined for this Recommendation. Subdivided into 3.1 "Terms defined elsewhere" and 3.2 "Terms defined in this Recommendation" (if both are used). See term formatting below. |32| 4 | **Abbreviations** *(optional)* | All abbreviations used in the text |33| 5 | **Conventions** *(optional)* | Any particular notation used |34| 6+ | **Text** | Body of the Recommendation |35| Annex A+ | **Integral annexes** | Normative material (same approval as Recommendation) |36| Annex (continues) | **Non-integral annexes** | Informative/supplementary (SG agreement, not full approval) |37| *(last, optional)* | **Bibliography** | Informative references not cited normatively; heading style `Appendix_No & title` with page break before |38| *(last)* | **Index** *(optional)* | |3940### Canonical skeleton template4142For new Recommendation drafting and for checking currently published Word43style definitions, use the local downloaded skeleton first:4445- `assets/itu-t-recommendation-skeleton.docx`4647Upstream source URL (for refresh):4849- `https://www.itu.int/en/ITU-T/studygroups/Documents/Doc-ITUT-Recs-Skelet.docx`5051### Term formatting (clause 3)5253Terms in clause 3 are formatted as **pseudo-subclauses**: they carry54subclause-style numbering (3.1.1, 3.1.2, ...) but are not real heading55paragraphs and do **not** appear in the table of contents.5657Each term follows this pattern:5859```text60<bold>3.1.N\tTERM NAME</bold>: definition text61```6263- The number prefix (`3.1.N`) and term name are **bold**64- A **tab** separates the number from the term name65- The term name ends with a **colon** and space, followed by the definition66 text (not bold)67- The paragraph uses `body-text` style with a manually set tab stop at68 1.5 cm (851 twips) — this tab stop is not part of the default69 `Normal` style in the ITU-T template7071This format applies to both 3.1 "Terms defined elsewhere" and723.2 "Terms defined in this Recommendation".7374### Subdivision numbering7576- Digits separated by periods: 1, 1.1, 1.1.177- No trailing period after single number78- Do not create subclause 1.1 unless 1.2 also exists7980______________________________________________________________________8182## Bibliography8384The Bibliography is an **optional, non-normative** clause containing85informative references (sources not cited normatively in the body).8687- **Position:** Always the last clause of the Recommendation, after all88 integral and non-integral annexes (and before the Index if present).89- **Heading:** Formatted with style `Appendix_No & title` (the same style90 used for non-integral appendix headings). Write only the word91 `Bibliography` — no number prefix.92- **Page break:** There **must** be a page break immediately before the93 Bibliography heading. Apply it as `pageBreakBefore: true` on the heading94 paragraph, not as a separate break paragraph.95- **Entries:** Each entry uses style `References` — the same style as96 normative reference entries in clause 2. Format: `[N]\t<citation text>`97 with a `{SEQ Ref \* ARABIC}` field and bookmark.9899See `itut-drafting` for the concrete style-name mapping and officecli100commands.101102______________________________________________________________________103104## Notes (from the Rules)105106- Integrated in text: shall **not** contain requirements. Use "NOTE -- " for107 single note, "NOTE 1 -- ", "NOTE 2 -- " for multiple.108- Notes to tables/figures: **may** contain requirements. Start with109 "NOTE 1 -- ". Located within table frame or above figure title.110- Notes are indented from the main text margin.111112______________________________________________________________________113114## Use of normative words115116| Word | Meaning |117|------|---------|118| **shall** | Mandatory requirement |119| **shall not** | Prohibition |120| **may** | Permission; indicates an action that is permitted but not required |121| **need not** | Negative of "may" (avoid "may not") |122123______________________________________________________________________124125## Figures and tables (from the Rules)126127### Figures128129- Numbered with Arabic numerals, independent of clauses (e.g. Figure 1, Figure 2)130- **Title below figure**, centred: "Figure x -- title"131- Referenced as "see Figure 1" (uppercase "F")132133### Tables134135- Numbered with Arabic numerals, independent of clauses (e.g. Table 1, Table 2)136- **Title above table**, centred: "Table x -- title"137- Columns framed, headings separated by horizontal line138- Spanning pages: "(continued)" / "Table x (concluded)"139140______________________________________________________________________141142## ITU-T | ISO/IEC common text143144When a Recommendation is jointly developed with ISO/IEC:145146### Terminology147148- **Common text**: Identical text in both ITU-T Rec and ISO/IEC IS149- **Identical Recommendations | International Standards**: Same text150- **Paired Recommendations | International Standards**: Technically aligned but not identical ("twin text")151152### Self-reference153154- In Scope/boilerplate: "this Recommendation | International Standard"155- Elsewhere: use a capitalized descriptive term (e.g. "this Specification")156157### Dual notation158159External references use ITU-T first: "see Rec. ITU-T X.882 | ISO/IEC 13712-3"160161### Title162163- Introductory element: "Information technology"164- Up to 3 elements, general to particular165- First letter of each element capitalized166167______________________________________________________________________168169## References170171- [references/rules-recommendation-structure.md](references/rules-recommendation-structure.md) -- detailed extract from Rules for presentation172173## Cross-references174175- `itut-basics` -- ITU-T organization, roles, meeting procedures176- `itut-contributions` -- contribution submission and TDocs177- `itut-drafting` -- ITU-T contribution .docx template and formatting178- `itut-patents` -- patent policy, IPR disclosure, licensing declarations179- `sdo-docx-formatting` -- formatting rules (delegated)