3.1  Document type

3.1.1

document

ISO or IEC standardization draft or publication

3.1.2

standard

document (3.1.1), established by consensus and approved by a recognized body, that provides, for common and repeated use, rules, guidelines or characteristics for activities or their results, aimed at the achievement of the optimum degree of order in a given context

[SOURCE: ISO/IEC GUIDE 2:2004, 3.2]

3.1.3

international standard

standard (3.1.2) that is adopted by an international standardizing/standards organization and made available to the public

[SOURCE: ISO/IEC GUIDE 2:2004, 3.2.1.1]

3.1.4

International Standard

international standard (3.1.3) where the international standards organization is ISO or IEC

3.1.5

Technical Specification

TS

document (3.1.1) published by ISO or IEC for which there is the future possibility (3.3.6) of agreement on an International Standard (3.1.4), but for which at present

• the required support for approval as an International Standard cannot be obtained,

• there is doubt on whether consensus has been achieved,

• the subject matter is still under technical development, or

• there is another reason precluding immediate publication as an International Standard

3.1.6

Publicly Available Specification

PAS

document (3.1.1) published by ISO or IEC to respond to an urgent market need, representing either

1. a consensus in an organization external to ISO or IEC, or

2. a consensus of the experts within a working group

3.1.7

Guide

document (3.1.1) published by ISO or IEC giving rules, orientation, advice or term recommendations, display recommendation not resolved via ID recommendations relating to international standardization

3.1.8

Technical Report

TR

document (3.1.1) published by ISO or IEC containing collected data of a different kind from that normally published as an International Standard (3.1.4) or Technical Specification (3.1.5)

3.2  Elements of a document

3.2.1

normative element

element that describes the scope of the document (3.1.1) or sets out term provisions, display provision not resolved via ID provisions

3.2.2

informative element

element intended to assist the understanding or use of the document (3.1.1) or that provides contextual information about its content, background or relationship with other documents

3.2.3

mandatory element

element that has to be present in a document (3.1.1)

3.2.4

conditional element

element that is present depending on the term provisions, display provision not resolved via ID provisions of the particular document (3.1.1)

3.2.5

optional element

element that the writer of a document (3.1.1) may choose to include or not

3.3  Provisions

3.3.1

provision

expression in the content of a normative document (3.1.1) that takes the form of a statement (3.3.2), an instruction, a recommendation (3.3.4) or a requirement (3.3.3)

[SOURCE: ISO/IEC GUIDE 2:2004, 7.1]

3.3.2

statement

expression, in the content of a document (3.1.1), that conveys information

3.3.3

requirement

expression, in the content of a document (3.1.1), that conveys objectively verifiable criteria to be fulfilled and from which no deviation is permitted if conformance with the document is to be claimed

3.3.4

recommendation

expression, in the content of a document (3.1.1), that conveys a suggested possible choice or course of action deemed to be particularly suitable without necessarily mentioning or excluding others

3.3.5

permission

expression, in the content of a document (3.1.1), that conveys consent or liberty (or opportunity) to do something

3.3.6

possibility

expression, in the content of a document (3.1.1), that conveys expected or conceivable material, physical or causal outcome

3.3.7

capability

expression, in the content of a document (3.1.1), that conveys the ability, fitness, or quality necessary to do or achieve a specified thing

3.3.8

external constraint

constraint or obligation on the user of the document (3.1.1) (e.g. laws of nature or particular conditions existing in some countries or regions) that is not stated as a provision (3.3.1) of the document

5.1  Planning and preparation

Rules for the planning and preparation of new work items are given in the ISO/IEC Directives, Part 1. The rules given in the ISO/IEC Directives and ISO and IEC Supplements shall be applied throughout all stages of drafting to avoid delay. In order to ensure the timely publication of a document or of a series of associated documents, the following shall be determined before drafting begins:

• the intended structure;

• any interrelationships;

• the organization and subdivision of the subject matter (see Clause 6).

In the case of a multipart document, a list of the intended parts should be drawn up (preferably including their titles and scopes).

5.2  Aim-oriented approach

Not all characteristics of an item or a subject can be or need to be standardized. The choice of characteristics to be standardized depends on the aims of the document (e.g. health, safety, protection of the environment, interface, interchangeability, compatibility or interworking, and variety control). A functional analysis of the product can help to identify the characteristics to be included in the document.

It is permitted, but not necessary, to give an explanation for the inclusion of individual characteristics. More general background information can be given in the Introduction (see Clause 13).

5.3  Fitness for implementation as a regional or national standard

Characteristics that are suitable for international acceptance shall be chosen. Where necessary, several options may be indicated (e.g. owing to differences in legislation, climate, environment, economies, social conditions, trade patterns).

The content of a document shall be written so that it can be applied and adopted without change as a regional or national standard.

See ISO/IEC Guide 21-1 for regional or national adoption of International Standards and ISO/IEC Guide 21-2 for regional or national adoption of other International Deliverables.

5.4  Performance principle

Whenever possible, requirements shall be expressed in terms of performance rather than design or descriptive characteristics. This principle allows maximum freedom for technical development and reduces the risk of undesirable market impacts (e.g. limiting development of innovative solutions).

When the performance principle is adopted, care shall be taken to ensure that important features are not inadvertently omitted from the performance requirements.

If it is impossible to determine the necessary performance characteristics, the material or product may be specified. However, in such a case, the phrase “… or any other material or product proved to be equally suitable” should be included.

Requirements concerning the manufacturing process shall usually be omitted in favour of tests to be made on the final product. There are, nevertheless, some fields in which reference to the manufacturing process is needed (e.g. hot rolling, extrusion) or even in which an inspection of the manufacturing process is necessary (e.g. pressure vessels).

However, the choice between specifying by description or by performance needs consideration because specification by performance can lead to complicated, costly and lengthy testing procedures.

5.5  Verifiability

Requirements shall be objectively verifiable. Only those requirements that can be verified shall be included.

Phrases such as “sufficiently strong” or “of adequate strength” shall not be used because they are subjective statements.

The stability, reliability or lifetime of a product shall not be specified if no test method is known that can verify the claim in a reasonably short time. A guarantee by the manufacturer is not a substitute for such requirements. Guarantee conditions shall not be included because they are commercial or contractual, rather than technical, in nature.

5.6  Consistency

Consistency should be maintained within each document, and within a series of associated documents.

• The structure of associated documents and the numbering of their clauses should, as far as possible, be identical.

• Identical wording should be used to express identical provisions.

• The same terminology should be used throughout. The use of synonyms should be avoided.

Consistency is particularly important to help the user understand documents or series of associated documents. It is also important when using automated text processing techniques and computer-aided translation.

5.7  Avoidance of duplication and unnecessary deviations

Documents should avoid duplication. This is particularly important in test methods, which are often applicable to more than one product, or type of product.

Before standardizing any item or subject, the writer shall determine whether an applicable standard already exists. If it is necessary to invoke a requirement that appears elsewhere, this should be done by reference, not by repetition – see Clause 10.

If a test method is, or is likely to be, applicable to two or more types of product, a document shall be prepared on the method itself, and each document dealing with a given product shall refer to it (indicating any modifications that could be necessary). This will help to prevent unnecessary deviations.

As far as possible, the requirements for one item or subject should be confined to one document.

In some fields, it can be desirable to write a document specifying generic requirements applicable to a group of items or subjects.

If it is considered necessary to repeat a requirement from an exterior source, its source shall be referenced precisely (see 10.1).

5.8  Accommodation of more than one product size

If the aim of a document is standardization of a single size for a product, but there is more than one widely accepted size in international use, a committee may decide to include alternative product sizes in the document. However, in such cases, every effort shall be made to reduce the number of alternatives to a minimum, taking the following points into account:

• the volume of international trade in the sort of product involved shall serve as a criterion for “international use”, not the number of countries or the volume of production in those countries;

• only sizes that are likely to be in international use in the reasonably foreseeable future (e.g. five years or more) shall be included in the document.

Whenever alternative solutions are to be adopted internationally, they shall all be included in the same document and preferences for the different alternatives shall be provided. The reasons for the preferences shall be explained in the introduction to the document.

When agreed by the committee and approved by the ISO Technical Management Board (ISO/TMB) or the IEC Standardization Management Board (IEC/SMB), a transitional period may be indicated during which the use of non-preferred values is permitted.

5.9  Characteristics not specified in a document

In some cases, a document may list characteristics that can be chosen freely by the supplier. The characteristics chosen shall be stated, for example on a name-plate, label or accompanying document.

For most kinds of complex item, it is impractical to specify exhaustive performance requirements. Instead, it is preferable to require that the item be supplied with a list of performance data.

This approach is not acceptable in the case of health and safety requirements.

Documents listing characteristics for which suppliers or purchasers are required to state values or other data not specified by the document shall specify how such values are to be measured and stated.

6.1  Names of the main subdivisions

The terms that shall be used to designate the divisions and subdivisions of subject matter are given in Table 1 in English and in French.

Table 1 — Names of divisions and subdivisions

English term	French term	Example of numbering
Part	Partie	9999-1
Clause Subclause Subclause Paragraph	Article Paragraphe Paragraphe Alinéa	1 1.1 1.1.1 [no number]
Annex	Annexe	A

6.2  Subdivision into documents

Documents are so diverse that no universally acceptable rules can be established for the subdivision of the subject matter.

However, as a general principle, an individual document shall be prepared for each subject to be standardized, and published either as a single standard or a single part of a series.

Such subdivision has the advantage that each part can be revised separately as necessary.

In particular, the aspects of a product that are of separate interest to different parties (e.g. manufacturers, certification bodies, legislative bodies or other users) shall be clearly distinguished, preferably as parts of a document or as individual documents.

6.3  Subdivision of the subject matter within a series of parts

There are two main ways of subdividing subject matter within a series of parts.

1. Each part deals with a specific aspect of the subject and can stand alone.

   EXAMPLE 1  Part 1: Vocabulary
   Part 2: Requirements
   Part 3: Test methods
   Part 4: …

   EXAMPLE 2  Part 1: Vocabulary
   Part 2: Harmonics
   Part 3: Electrostatic discharge
   Part 4: …

2. There are both common and specific aspects to the subject. The common aspects shall be given in Part 1. Specific aspects (which can modify or supplement the common aspects and therefore cannot stand alone) shall be given in separate individual parts.

   EXAMPLE 3  Part 1: General requirements
   Part 2: Thermal requirements
   Part 3: Air purity requirements
   Part 4: Acoustical requirements

   EXAMPLE 4  Part 1: General requirements
   Part 21: Particular requirements for electric irons
   Part 22: Particular requirements for spin extractors
   Part 23: Particular requirements for dishwashers

   EXAMPLE 5  For IEC documents only
   Part 1: General requirements
   Part 2-1: Requirements for plasma displays
   Part 2-2: Requirements for monitors
   Part 2-3: Requirements for LCDs

Where the system described in b) is used, care shall be taken that the references from one part to another are valid. There are two ways of achieving this.

• If reference is made to a particular element, the reference shall be dated (see 10.5).

• When undated references (see 10.4) are used, the committee responsible shall validate the references at the time of review of the document.

Each part of a multipart document shall be drafted in accordance with the same rules as those used for an individual document.

The number of a part shall be in Arabic numerals, starting with 1, following the document number and preceded by a hyphen.

In ISO, parts cannot be further subdivided. In IEC, parts can be subdivided down to two levels. See the examples in 11.4.

If a document is subdivided in a number of separate parts, the first part should include an explanation of the intended structure in its introduction. When developing a series, consider reserving Part 1 for general aspects such as a vocabulary.

In the Foreword of each part in the series, a reference may be made to the titles of all other parts that have been or are planned to be published.

6.4  Subdivision of the subject matter within an individual document

An example of a typical arrangement is given in Table 2.

Table 2 — Overview of the major subdivisions of a document and their arrangement in the text

Major subdivision	Mandatory/Optional/Conditional
Title	Mandatory
Foreword	Mandatory
Introduction	Optional/Conditionala
Scope	Mandatory
Normative references	Mandatoryb
Terms and definitions	Mandatoryb
Symbols and abbreviated terms	Conditional
Technical content For example: test methods	Mandatory/Optional/Conditional
Annexes	Optional
Bibliography	Conditional
a  See 13.3. b  When no normative references or terms are listed, use the introductory texts provided in 15.5.2 and 16.5.3.

7.1  General

The user of the document needs to be able to identify the requirements he/she is obliged to satisfy in order to claim compliance with a document. The user also needs to be able to distinguish these requirements from other types of provision where there is a choice (i.e. recommendations, permissions, possibilities and capabilities).

It is essential to follow rules for the use of verbal forms so that a clear distinction can be made between requirements, recommendations, permissions, possibilities and capabilities.

The first column in Table 3 to Table 7 shows the preferred verbal form to be used to express each type of provision. The equivalent expressions given in the second column shall be used only in certain cases when the form given in the first column cannot be used for linguistic reasons.

Only singular forms are shown in Table 3 to Table 7.

7.2  Requirement

See the definition given in 3.3.3.

The verbal forms shown in Table 3 shall be used to express requirements.

Table 3 — Requirement

Preferred verbal form	Equivalent phrases or expressions for use in certain cases
shall	is to is required to it is required that has to only … is permitted it is necessary
shall not	is not allowed [permitted] [acceptable] [permissible] is required to be not is required that … be not is not to be do not
EXAMPLE 1  Connectors shall conform to the electrical characteristics specified by IEC 60603-7-1.
Imperative mood: The imperative mood is frequently used in English to express requirements in procedures or test methods. EXAMPLE 2  Switch on the recorder. EXAMPLE 3  Do not activate the mechanism before…
Do not use “must” as an alternative for “shall”. This avoids confusion between the requirements of a document and external constraints (see 7.6). Do not use “may not” instead of “shall not” to express a prohibition.

7.3  Recommendation

See the definition given in 3.3.4.

The verbal forms shown in Table 4 shall be used to express recommendations.

Table 4 — Recommendation

Preferred verbal form	Equivalent phrases or expressions for use in certain cases
should	it is recommended that ought to
should not	it is not recommended that ought not to
EXAMPLE  Wiring of these connectors should take into account the wire and cable diameter of the cables defined in IEC 61156.
In French, do not use “devrait” in this context.

7.4  Permission

See the definition given in 3.3.5.

The verbal forms shown in Table 5 shall be used to express permission.

Table 5 — Permission

Preferred verbal form	Equivalent phrases or expressions for use in certain cases
may	is permitted is allowed is permissible
may not	it is not required that no … is required
EXAMPLE 1  IEC 60512-26-100 may be used as an alternative to IEC 60512-27-100 for connecting hardware that has been previously qualified to IEC 60603-7-3:2008. EXAMPLE 2  Within an EPB document, if the quantity is not passed to other EPB documents, one or more of the subscripts may be omitted provided that the meaning is clear from the context.
Do not use “possible” or “impossible” in this context. Do not use “can” instead of “may” in this context. Do not use “might” instead of “may” in this context. “May” signifies permission expressed by the document, whereas “can” refers to the ability of a user of the document or to a possibility open to him/her. The French verb “pouvoir” can indicate both permission and possibility. If there is a risk of misunderstanding, the use of other expressions is advisable.

7.5  Possibility and capability

See the definitions given in 3.3.6 and 3.3.7.

The verbal forms shown in Table 6 shall be used to express possibility and capability.

Table 6 — Possibility and capability

Preferred verbal form	Equivalent phrases or expressions for use in certain cases
can	be able to there is a possibility of it is possible to
cannot	be unable to there is no possibility of it is not possible to
EXAMPLE 1  Use of this connector in corrosive atmospheric conditions can lead to failure of the locking mechanism. EXAMPLE 2  These measurements can be used to compare different sprayer setups on the same sprayer. EXAMPLE 3  Only the reverse calculation approach given in E.3 can be used for calculated energy performance. EXAMPLE 4  The sum over time can be related either to consecutive readings or to readings on different time slots (e.g. peak versus off-peak).
Do not use “may” instead of “can” in this context. “May” signifies permission expressed by the document, whereas “can” refers to the ability of a user of the document or to a possibility open to him/her. The French verb “pouvoir” can indicate both permission and possibility. If there is a risk of misunderstanding, the use of other expressions is advisable.

7.6  External constraint

See the definition given in 3.3.8.

External constraints are not requirements of the document. They are given for the information of the user.

The verbal form shown in Table 7 shall be used to indicate constraints or obligations defined outside the document.

Table 7 — External constraint

Preferred verbal form	Equivalent phrases or expressions for use in certain cases
must
EXAMPLE 1  Particular conditions existing in a country: Because Japan is a seismically active country, all buildings must be earthquake-resistant. EXAMPLE 2  A law of nature: All fish must maintain a balance of salt and water in their bodies to stay healthy.
Do not use “must” as an alternative for “shall”. This avoids confusion between the requirements of a document and external constraints (see 7.2).

8.1  Language versions

The general policy on languages is explained in the ISO/IEC Directives, Part 1.

The different language versions of documents shall be technically equivalent and structurally identical.

The use of bilingualism from the initial stage of drafting is of great assistance in the preparation of clear and unambiguous texts.

Documents containing text in languages additional to the official languages shall contain the following text (completed as appropriate) in the Foreword.

8.2  Spelling reference works

The following reference works for spelling are suggested:

• for English, The Shorter Oxford English Dictionary, The Concise Oxford Dictionary, The Collins Concise English Dictionary, Webster’s New World College Dictionary or Chambers Concise Dictionary;

• for French, Dictionnaire Le Robert, Dictionnaire Larousse and Dictionnaire des difficultés de la langue française (V. Thomas, Larousse).

8.3  Spelling and abbreviated forms of names of organizations

The names of organizations, and their abbreviated forms, shall be written as used by those organizations, in English, French or Russian.

8.4  Abbreviated terms

The use of abbreviated terms shall be consistent throughout the document.

If a list of abbreviated terms is not given in the document (see Clause 17), then the first time that an abbreviated term is used, the full term shall be given with the abbreviated term following in brackets.

Any abbreviated term should be in upper case letters, without a full stop after each letter.

Occasionally, abbreviated terms in common use are written differently, either for historical or for technical reasons.

Technical specifications regarding marking may impose other requirements.

8.5  Linguistic style

To help users understand and use the document correctly, the linguistic style shall be as simple and concise as possible. This is particularly important for those users whose first language is not one of the official languages of ISO and IEC.

9.1  Representation of numbers and numerical values

• The decimal sign shall be a comma on the line in all language versions.

• To express values of physical quantities, Arabic numerals followed by the international symbol for the unit shall be used (see ISO 80000, IEC 80000 and IEC 60027).

• If the magnitude (absolute value) of a number less than 1 is written in decimal form, the decimal sign shall be preceded by a zero.

  EXAMPLE 1  0,001

• Each group of three digits shall be separated by a small space from the preceding digits. This also applies to digits following the decimal sign. This does not apply to binary and hexadecimal numbers, numbers designating years or the numbering of standards.

  EXAMPLE 2  $\mathrm{23,456}$       $\mathrm{2,345}$       $2.345$       $2.3456$       $2.34567$ but the year 2011

• The multiplication cross ($\times$) shall be used to indicate the multiplication of numbers and numerical values written in decimal form, in vector products and in cartesian products.

  EXAMPLE 3  $A=80\text{ mm}\times 25\text{ mm}$

  EXAMPLE 4  $l=2.5x{10}^3\text{ m}$

  EXAMPLE 5  ${\overrightarrow{I}}_G={\overrightarrow{I}}_1\times {\overrightarrow{I}}_2$

• The half-high dot (·) shall be used to indicate a scalar product of vectors and comparable cases, and may also be used to indicate a product of scalars and in compound units.

  EXAMPLE 6  $U=R\cdot I$

  EXAMPLE 7  $\mathrm{rad}\cdot m^2\cdot {\mathrm{kg}}^{-1}$

• In some cases, the multiplication sign may be omitted.

  EXAMPLE 8  $4c-5d$         $6ab$         $7(a+b)$         $3\ln 2$

• ISO 80000-2 gives an overview of multiplication symbols for numbers.

9.2  Values, dimensions and tolerances

9.3  Quantities, units, symbols and signs

• The International System of units (SI) as set out in ISO 80000 and IEC 80000 shall be used.

• The units in which any values are expressed shall be indicated.

• The unit symbols for degree, minute and second for plane angle shall immediately follow the numerical value; all other unit symbols shall be preceded by a space.

• Symbols for quantities shall be chosen, wherever possible, from the various parts of IEC 60027, ISO 80000 and IEC 80000.

• Language-specific abbreviated terms such as ppm should not be used, if possible. If it is necessary to use language-specific abbreviated terms such as ppm, their meaning shall be explained.

• Mathematical signs and symbols shall be in accordance with ISO 80000-2.

Use Annex B as a checklist of the quantities and units which shall be used.

10.1  Purpose or rationale

The entire collection of International Standards published by ISO and IEC is interrelated and forms a system whose integrity has to be preserved.

Therefore, references to particular pieces of text should be used instead of repetition of the original source material. Repetition introduces the risk of error or inconsistency and increases the length of the document. However, if it is considered necessary to repeat such material, its source shall be referenced precisely.

Imprecise references such as “the following clause” or “the figure above” shall not be used.

References can be made

• to other parts of the document (e.g. a clause, table or figure — see 10.6), or

• to other documents or publications (see 10.2).

References can be

• informative (see Clause 21), or

• normative (see Clause 15).

References can be

• dated (see 10.5), or

• undated (see 10.4).

For management system standards, the rules of the ISO/IEC Directives, Part 1, Consolidated ISO Supplement apply.

10.2  Permitted referenced documents

Normatively referenced documents shall be documents published by ISO or IEC. In the absence of appropriate ISO or IEC documents, those published by other bodies may be listed as normative references provided that

1. the referenced document is recognized by the committee as having wide acceptance and authoritative status,

2. the committee has the agreement of the authors or publishers (where known) of the referenced document for its inclusion as a reference,

3. the authors or publishers (where known) have also agreed to inform the committee of their intention to revise the referenced document and what points the revision will affect,

4. the document is available under commercial terms which are fair, reasonable and non-discriminatory, and

5. any patented item required for the implementation of the ISO and/or IEC deliverable in the referenced document is available to be licensed in accordance with subclause 2.14 of the ISO/IEC Directives, Part 1, 2018, “Reference to patented items”.

Informative reference may be made to any other type of document. Informative references shall be listed in the Bibliography.

ISO and IEC normatively referenced documents shall have reached at least the enquiry stage (40.20 DIS or CDV).

The committees shall validate all referenced documents when a document is revised.

The normative references list shall not include the following:

• referenced documents which are not publicly available (in this context, “publicly available” means published documents which are available free of charge, or available commercially under reasonable and non-discriminatory terms to any user);

• referenced documents which are cited only informatively as bibliographic or background material.

10.3  Presentation of references

Documents shall be referred to by their number, and if applicable, date of publication and title.

For other referenced documents and information resources (printed, electronic or otherwise), the relevant rules set out in ISO 690 shall be followed.

For online referenced documents, information sufficient to identify and locate the source shall be provided. Preferably, the primary source of the referenced document should be cited, in order to ensure traceability.

The information shall include the method of access to the referenced document and the full network address, with the same punctuation and use of upper case and lower case letters as given in the source (see ISO 690).

Furthermore, the referenced document should be expected to remain valid for the expected life of the referring document.

10.4  Undated references

Undated references may be made:

• only to a complete document;

• if it will be possible to use all future changes of the referenced document for the purposes of the referring document;

• when it is understood that the reference will include all amendments to and revisions of the referenced document.

The date of publication or dash (see 10.5) shall not be given for undated references. When an undated reference is to all parts of a document, the standard identifier shall be followed by “(all parts)”.

In the Normative references clause or Bibliography, use the following forms to list undated references.

In the text, use the following forms to make undated references to a document.

10.5  Dated references

Dated references are references to

• a specific edition, indicated by the date of publication, or

• a specific enquiry or final draft, indicated by a dash.

Normative references to enquiry or final drafts are potentially risky, and are strongly discouraged, as the referenced document can change before publication.

For dated references, each shall be given with its year of publication, or, in the case of enquiry or final drafts, with a dash together with a footnote, such as “Under preparation”.

The date of publication shall be indicated by the year or, for documents for which more than one edition of the document or an element within the document will be published in the same calendar year, the year of publication and the month (and, where necessary, the day).

If the referenced document is amended or revised, the dated references to it will need to be reviewed to assess whether they should be updated or not.

In this context, a part is regarded as a separate document.

Within the text, references to specific elements (e.g. clauses or subclauses, tables and figures) of a referenced document shall always be dated, because subsequent editions could result in the renumbering of such elements within the referenced document.

In the Normative references clause or Bibliography, use the following forms to list dated references.

In the text, use the standard identifier rather than the title when referring to an ISO or IEC publication. The titles are usually only written out in full in the Normative references clause and in the Bibliography.

In the text, use the following forms to make dated references to a document.

10.6  References in a document to itself

References shall not be made to page numbers, since pagination can change if the referenced document is published in different formats, or if the document is revised.

For an individual document, the form “this document” shall be used.

For a document published in separate parts, the standard identifier followed by the phrase “(all parts)” shall be used to refer to the entire series.

Such undated references are understood to include all amendments and revisions to the referenced document.

11.1  Purpose or rationale

The title is a clear, concise description of the subject matter covered by the document. It is drafted so as to distinguish the subject matter from that of other documents, without going into unnecessary detail. Any necessary additional details are given in the Scope.

11.2  Normative or informative?

The title is a normative element.

11.3  Mandatory, conditional or optional?

The title is a mandatory element.

11.4  Numbering and subdivision

The title is composed of separate elements, each as short as possible, proceeding from the general to the particular, for example:

1. an introductory element indicating the general field to which the document belongs (this can often be based on the title of the committee which prepared the document);

2. a main element indicating the principal subject treated within that general field;

3. a complementary element indicating the particular aspect of the principal subject or giving details that distinguish the document from other documents, or other parts of the same document.

No more than three elements shall be used. The main element shall always be included.

The title of a part shall be composed in the same way. All the individual titles in a series of parts shall contain the same introductory element (if present) and main element, while the complementary element shall be different in each case in order to distinguish the parts from one another. The complementary element shall be preceded in each case by the designation “Part …:”.

When a document is divided into subparts (in the IEC), the parts within each subseries shall have the same subseries title.

11.5  Specific principles and rules

12.1  Purpose or rationale

The Foreword provides information on:

• the organization responsible for publishing the document;

• the committee that developed the document;

• the procedures and rules under which the document was developed;

• the voting process;

• legal disclaimers;

• relationships between the present document and other documents.

12.2  Normative or informative?

The Foreword is an informative element. It shall not contain requirements, permissions or recommendations.

12.3  Mandatory, conditional or optional?

The Foreword is a mandatory element.

12.4  Numbering and subdivision

The Foreword shall not have a clause number and shall not be subdivided.

12.5  Specific principles and rules

13.1  Purpose or rationale

The Introduction provides specific information or commentary about the technical content of the document, and about the reasons prompting its preparation.

13.2  Normative or informative?

The Introduction is an informative element. It shall not contain requirements.

13.3  Mandatory, conditional or optional?

The Introduction is an optional element. It is only mandatory if a specific patent right has been identified during the development of the document.

13.4  Numbering and subdivision

The Introduction shall not have a clause number. If there is a need to create numbered subdivisions, the subclauses are numbered 0.1, 0.2, etc. Any figure, table, displayed formula or footnote shall be numbered starting with 1.

13.5  Specific principles and rules

Whenever alternative solutions are offered in a document and preferences for the different alternatives provided, the reasons for the preferences shall be explained in the Introduction.

Where patent rights have been identified in a document, the Introduction shall include an appropriate notice. See Clause 30.

14.1  Purpose or rationale

The Scope clearly defines the subject of the document and the aspects covered, thereby indicating the limits of applicability of the document or particular parts of it.

If necessary, the Scope should indicate subjects that might be reasonably inferred to be covered but actually excluded from the document.

In documents that are subdivided into parts, the Scope of each part shall define the subject of that part of the document only.

The Scope shall be succinct so that it can be used as a summary for bibliographic purposes, for example, as an abstract. If further details and background information are necessary, these shall be included in either the Introduction or in an annex.

14.2  Normative or informative?

The Scope is a normative element. It shall not contain requirements, permissions or recommendations.

14.3  Mandatory, conditional or optional?

The Scope is a mandatory element.

14.4  Numbering and subdivision

The Scope shall be numbered as Clause 1. It may be subdivided; however, this is not normally necessary as it is meant to be succinct.

14.5  Specific principles and rules

The Scope shall only appear once in each document and shall be worded as a series of statements of fact.

Forms of expression such as the following shall be used:

“This document

• specifies

  the dimensions of …”
  a method of …”
  the characteristics of …”

• establishes

  a system for …”
  general principles for …”

• gives guidelines for …”

• defines terms …”

Statements of applicability of the document shall be introduced by wording such as:

• “This document is applicable to …”

• “This document does not apply to …”

15.1  Purpose or rationale

The Normative references clause lists, for information, those documents which are cited in the text in such a way that some or all of their content constitutes requirements of the document.

Information on how these references apply is found in the place where they are cited in the document, and not in the Normative references clause.

15.2  Normative or informative?

The Normative references clause is an informative element.

The list of references it contains is given for the convenience of the user, who can then consult the place where they are cited in the document to understand and assess how they apply.

15.3  Mandatory, conditional or optional?

The Normative references clause is a mandatory element, even if it contains no normative references.

15.4  Numbering and subdivision

The Normative references clause shall be numbered as Clause 2. It shall not be subdivided.

Referenced documents listed are not numbered.

15.5  Specific principles and rules

16.1  Purpose or rationale

The Terms and definitions clause provides definitions necessary for the understanding of certain terms used in the document.

If necessary, terminological entries can be supplemented by information (including requirements) given in the notes to entry.

Terminology may take the form of an independent terminology standard (a vocabulary, nomenclature, or list of equivalent terms in different languages) or be included in a Terms and definitions clause in a document that also deals with other aspects.

16.2  Normative or informative?

The Terms and definitions clause is a normative element. It defines the way in which the listed terms shall be interpreted.

16.3  Mandatory, conditional or optional?

The Terms and definitions clause is a mandatory element, even if it contains no terminological entries.

16.4  Numbering and subdivision

The Terms and definitions clause shall be numbered as Clause 3. It may be subdivided. Terminological entries shall be numbered. The numbering and structure shall be identical in all language versions.

Terms and definitions should preferably be listed according to the hierarchy of the concepts (i.e. systematic order). Alphabetical order is the least preferred order.

For convenience, the symbols and abbreviated terms may be combined with the terms and definitions in order to bring together terms and their definitions, symbols and abbreviated terms under an appropriate composite title, for example “Terms, definitions, symbols and abbreviated terms”.

16.5  Specific principles and rules

16.6  Overview of the main elements of a terminological entry

Figure 1 gives an overview of the main elements of a terminological entry.

16.7  Other elements of a terminological entry

Other data categories may be included in a terminological entry, such as:

• country codes;

• grammatical information;

• pronunciation.

Refer to ISO 10241-1 for the general requirements and examples.

17.1  Purpose or rationale

The symbols and abbreviated terms clause or subclause provides a list of the symbols and abbreviated terms used in the document, along with their definitions.

17.2  Normative or informative?

The symbols and abbreviated terms clause is a normative element.

17.3  Mandatory, conditional or optional?

The symbols and abbreviated terms clause is a conditional element.

17.4  Numbering and subdivision

The symbols do not need to be numbered. For convenience, the symbols and abbreviated terms may be combined with the terms and definitions in order to bring together terms and their definitions, symbols and abbreviated terms under an appropriate composite title, for example “Terms, definitions, symbols and abbreviated terms”.

17.5  Specific principles and rules

Only symbols used in the text shall be listed.

Unless there is a need to list symbols in a specific order to reflect technical criteria, all symbols should be listed in alphabetical order in the following sequence:

• upper case Latin letter followed by lower case Latin letter (A, a, B, b, etc.);

• letters without indices preceding letters with indices, and with letter indices preceding numerical ones (B, b, C, C_m, C₂, c, d, d_ext, d_int, d₁, etc.);

• Greek letters following Latin letters (Z, z, Α, α, Β, β, …, Λ, λ, etc.);

• any other special symbols.

18.1  Purpose or rationale

Measurement and test methods specify the procedure for determining the values of characteristics or for checking conformity to stated requirements. Using a standardized test method ensures comparability of the results.

Measurement and test methods may be presented as separate clauses, or be incorporated in the requirements, or be presented as annexes (see Clause 20) or as separate parts (see 6.3). A measurement and test method shall be prepared as a separate document if it is likely to be referred to in a number of other documents.

18.2  Normative or informative?

The measurement and test methods clause is a normative element.

18.3  Mandatory, conditional or optional?

The measurement and test methods clause is a conditional element.

18.4  Numbering and subdivision

Measurement and test methods may be subdivided in the following order (where appropriate):

1. principle;

2. reagents and materials (see 18.5.3);

3. apparatus (see 18.5.4);

4. preparation and preservation of test samples and test pieces;

5. procedure;

6. expression of results, including method of calculation and precision of the test method, and, in ISO, the measurement uncertainty;

7. test report.

When health, safety or environmental warnings are needed, these should be placed next to the relevant content in the test method. General warnings should be placed at the beginning of the test method.

18.5  Specific principles and rules

19.1  Purpose or rationale

Marking, labelling and packaging are important aspects related to product manufacturing and procurement that frequently need a standardized approach, particularly in safety critical applications.

19.2  Normative or informative?

Marking, labelling and packaging clauses are usually normative elements although exceptions can exist (e.g. when only recommendations are made concerning marking, labelling and packaging).

19.3  Mandatory, conditional or optional?

Marking, labelling and packaging clauses are conditional elements.

19.4  Specific principles and rules

20.1  Purpose or rationale

Annexes are used to provide additional information to the main body of the document and are developed for several reasons, for example:

• when the information or table is very long and including it in the main body of the document would distract the user;

• to set apart special types of information (e.g. software, example forms, results of interlaboratory tests, alternative test methods, tables, lists, data);

• to present information regarding a particular application of the document.

20.2  Normative or informative?

Annexes can be normative or informative elements.

Normative annexes provide additional normative text to the main body of the document.

Informative annexes provide additional information intended to assist the understanding or use of the document. Informative annexes may contain optional requirements. For example, a test method that is optional may contain requirements but there is no need to comply with these requirements to claim compliance with the document. The status of the annex (informative or normative) shall be made clear by the way in which it is referred to in the text and shall be stated under the heading of the annex.

20.3  Mandatory, conditional or optional?

Annexes are optional elements.

20.4  Numbering and subdivision

Each annex shall be designated by a heading comprising the word “Annex” followed by a capital letter, starting with “A”, for example “Annex A”. The annex heading shall be followed by the indication “(normative)” or “(informative)”, and by the title.

Annexes may be subdivided into clauses, subclauses, paragraphs and lists.

Numbers given to the clauses, subclauses, tables, figures and mathematical formulae of an annex shall be preceded by the letter designating that annex followed by a full stop. The numbering shall start afresh with each annex.

20.5  Specific principles and rules

Each annex shall be explicitly referred to within the text.

21.1  Purpose or rationale

The Bibliography lists, for information, those documents which are cited informatively in the document, as well as other information resources.

21.2  Normative or informative?

The Bibliography is an informative element. It shall not contain requirements, permissions or recommendations.

21.3  Mandatory, conditional or optional?

The Bibliography is a conditional element. Its inclusion is dependent on whether informative references are present in the document.

21.4  Numbering and subdivision

The Bibliography shall not have a clause number. It may be subdivided in order to group the referenced documents under descriptive headings. Such headings shall not be numbered.

Referenced documents and information resources listed may be numbered.

21.5  Specific principles and rules

The Bibliography, if present, shall appear after the last annex.

Referenced documents and information resources listed can be dated or undated. See 10.4 and 10.5.

22.1  Purpose or rationale

Clauses and subclauses serve as the basic components in the subdivision of the content of a document.

22.2  Title

Each clause shall have a title.

Each first level subclause (e.g. 5.1, 5.2) should preferably be given a title. Within a clause or subclause, the use of titles shall be uniform for subclauses at the same level, for example if 10.1 has a title, 10.2 shall also have a title. Figure 2 shows examples of correct and incorrect use of subclause titles.

22.3  Numbering, subdivision and hanging paragraphs

22.4  Referencing

Clauses and subclauses do not need to be specifically referred to in the text.

Use, for example, the following forms for references to clauses and subclauses:

• “in accordance with Clause 4”;

• “details as given in 4.1.1”;

• “the requirements given in B.2”;

• “the methods described in 5.3 provide further information on…​”.

23.1  Purpose or rationale

A list serves to subdivide information to aid understanding.

23.2  Title

Lists do not have a title. They may, however, be preceded by a title or introductory phrase.

23.3  Numbering and subdivision

Lists can be numbered or unnumbered. Lists can be subdivided.

See the examples below.

23.4  Referencing

The purpose of a list should be made clear by its context. For example, an introductory proposition or a subclause title can serve to introduce the list. Lists do not need to be specifically referred to in the text.

If cross-references to list items are necessary, a numbered list shall be used. Within a subdivision, each list item in a numbered list shall have a unique identifier. Numbering restarts at each new clause or subclause.

Use, for example, the following forms for references to lists:

• “as specified in 3.1 b)”;

• “the requirements given in B.2 c)”.

24.1  Purpose or rationale

Notes are used for giving additional information intended to assist the understanding or use of the text of the document. The document shall be usable without the notes.

For rules on notes to figures, see 28.5.4.

For rules on notes to tables, see 29.5.1.

Notes to entry (in terminological entries) follow different rules from those for notes, see 16.5.9. Table 8 summarizes how to use notes and footnotes within documents.

Table 8 — Use of notes and footnotes within documents

	Element	Rule	Numbering	Designation	Provisions allowed?
In terminology	Note # to entry	16.5.9	Always numbered	Note 1 to entry, Note 2 to entry, etc.	May contain provisions (shall, should or may) related to the use of the term
	Footnotes to terminological entries are not allowed	16.5.11
In the text	Note	24.1	Numbered if more than one; numbering restarts for each new clause or subclause	NOTE 1, NOTE 2, etc.	No requirements (shall) or any information considered indispensable for the use of the document, recommendations (should) or permissions (may)
	Footnote	26.1	Sequential throughout the document	Normally with Arabic numerals	No requirements (shall) or any information considered indispensable for the use of the document, recommendations (should) or permissions (may)
Figures	Notes to figures	28.5.4	Numbered if more than one; numbered independently from the notes to the text; numbering restarts for each new figure	NOTE 1, NOTE 2, etc.	No requirements (shall) or any information considered indispensable for the use of the document, recommendations (should) or permissions (may)
	Footnotes to figures	28.5.5	Numbered if more than one; numbered independently from the footnotes to the text; numbering restarts for each new figure	Normally superscript lower case letters, starting with “a”	May contain requirements
Tables	Notes to tables	29.5.1	Numbered if more than one; numbered independently from the notes to the text; numbering restarts for each new table	NOTE 1, NOTE 2, etc.	No requirements (shall) or any information considered indispensable for the use of the document, recommendations (should) or permissions (may)
	Footnotes to tables	29.5.2	Numbered if more than one; numbered independently from the footnotes to the text; numbering restarts for each new table	Normally superscript lower case letters, starting with “a”	May contain requirements

24.2  Title

Notes do not have a title.

24.3  Numbering and subdivision

Within a given clause or subclause, notes shall be numbered sequentially. The numbering restarts at each new subdivision. A single note in a subdivision does not need to be numbered.

24.4  Referencing

Notes do not need to be specifically referred to in the text.

If notes are referred to, use for example, the following forms for references:

• “an explanation is provided in 7.1, Note 2”;

• “see 8.6, Note 3”.

24.5  Specific principles and rules

Notes shall not contain requirements (e.g. use of “shall”, see Table 3) or any information considered indispensable for the use of the document, for example instructions (imperative mood), recommendations (e.g. use of “should”, see Table 4) or permission (e.g. use of “may”, see Table 5). Notes should be written as a statement of fact.

Table 8 summarizes how to use notes and footnotes within documents.

24.6  Examples

25.1  Purpose or rationale

Examples illustrate concepts presented in the document. The document shall be usable without the examples.

25.2  Title

Examples do not need to have a title, but they can, if necessary, be grouped into a clause or subclause entitled “Example” or “Examples” (see 25.6, which is titled “Examples”).

25.3  Numbering and subdivision

Within a given clause or subclause, examples shall be numbered sequentially. The numbering restarts at each new subdivision. A single example in a subdivision does not need to be numbered.

25.4  Referencing

Examples do not need to be specifically referred to in the text.

If examples are referred to, use for example, the following forms for references:

• “see 6.6.3, Example 5”;

• “Clause 4, Example 2 lists …”.

25.5  Specific principles and rules

Examples shall not contain requirements (use of “shall”) or any information considered indispensable for the use of the document, for example instructions (imperative mood), recommendations (use of “should”) or permission (use of “may”). Examples should be written as a statement of fact.

An example can cite text to illustrate a point. If the cited text contains requirements, recommendations and permissions, this is acceptable.

25.6  Examples

26.1  Purpose or rationale

Footnotes to the text of a document are used to give additional contextual information to a specific item in the text. The document shall be usable without the footnotes.

For rules on footnotes to figures, see 28.5.5.

For rules on footnotes to tables, see 29.5.2.

26.2  Title

Footnotes do not have a title.

26.3  Numbering and subdivision

Footnotes shall be numbered sequentially throughout the document. Normally, footnote references are indicated using Arabic numerals. Exceptionally, other systems (a, b, c, etc.; , , , etc.; †, ‡, etc.) can be used, for example when there is the possibility of confusing them with superscript numbers.

26.4  Referencing

Footnotes shall be referenced in the text.

Use, for example, the following form for references to footnotes:

• ISO 1234:–¹ lists the test methods for…

‌——————-

¹ Under preparation. Stage at the time of publication: ISO/DIS 1234:2014.

26.5  Specific principles and rules

A footnote can appear anywhere within the text of a document apart from terminological entries.

Footnotes shall not contain requirements (e.g. use of “shall”, see Table 3) or any information considered indispensable for the use of the document, for example instructions (imperative mood), recommendations (e.g. use of “should”, see Table 4) or permission (e.g. use of “may”, see Table 5). Footnotes should be written as a statement of fact.

26.6  Examples

27.1  Purpose or rationale

A mathematical formula uses symbols to express the relationship between quantities.

27.2  Title

Mathematical formulae do not have a title.

27.3  Numbering and subdivision

If needed for cross-referencing purposes, mathematical formulae can be numbered in a document. Arabic numbers in parentheses shall be used, starting with 1.

The numbering shall be continuous and independent of the numbering of clauses, tables and figures. Subdivision of mathematical formulae [for example (2a), (2b), etc.] is not permitted.

When mathematical formulae in annexes are numbered, the numbering restarts and is preceded by the annex letter.

27.4  Referencing

If a formula is numbered, it should be referred to in the text. The purpose of a formula should be made clear by its context, for example, with an introductory proposition.

Use, for example, the following forms for references to mathematical formulae:

• “see 10.1, Formula (3)”;

• “see A.2, Formula (A.5)”.

27.5  Specific principles and rules

Mathematical formulae shall be expressed in mathematically correct form.

The variables shall be represented by italicized single-letter symbols. The meanings of the symbols shall be explained in connection with the mathematical formulae, unless they appear in a symbols and abbreviated terms clause.

However, the same symbol shall never be used within a document both for a quantity and for its corresponding numerical value. For example, use of the formula in Example 1 and of the formula in Example 2 in the same context would imply that $1=3.6$ (which obviously is not true).

If, exceptionally, a formula between numerical values is used, the style shown in Example 2 shall be followed.

Descriptive terms or names of quantities shall not be arranged in the form of a mathematical formula. Names of quantities or multiletter abbreviated terms, for example presented in italics or with subscripts, shall not be used in the place of symbols.

The same symbol should not be used to represent different quantities within the same document. Subscripts can be useful to distinguish symbols for related concepts.

Unit symbols shall not be used within mathematical formulae.

Further examples are presented in Annex B.

28.1  Purpose or rationale

Figures are a graphical means of representation used when they are the most efficient means of presenting information in an easily comprehensible form.

Photographs and other media may be used if it is not possible to represent the concept as a line drawing.

28.2  Title

It is recommended to provide a concise figure title.

28.3  Numbering and subdivision

28.4  Referencing

Each figure shall be explicitly referred to within the text.

Use, for example, the following forms for references to figures and subfigures:

• “Figure 3 illustrates…”;

• “See Figure 6 b)”.

28.5  Specific principles and rules

28.6  Types of figure

29.1  Purpose or rationale

Tables are used when they are the most efficient means of presenting information in an easily comprehensible form.

29.2  Title

It is recommended to provide a concise table title.

29.3  Numbering and subdivision

Tables shall be designated “Table” and numbered with Arabic numerals, beginning with 1. A single table shall be designated “Table 1”. This numbering shall be independent of the numbering of the clauses and of any figures.

Further subdivision [e.g. Table 1 a)] is not permitted. A table within a table is not permitted. Subdivision of a table into subsidiary sections with new column headings is not permitted.

It is often better to create several tables rather than trying to consolidate too much information into one table. The simpler the presentation, the better.

If a very complex table is necessary, it can be better to include it as a software supplement to the document.

In annexes, the table numbering restarts and the number is preceded by the annex letter (e.g. Table A.1).

When a table is continued over several pages, it can be useful to indicate the continuation.

The column headings together with any statement concerning units can be repeated on all pages after the first.

29.4  Referencing

Each table shall be explicitly referred to within the text.

Use, for example, the following forms for references to tables:

• “Table 3 lists…”;

• “See Table B.1”.

29.5  Specific principles and rules

29.6  Examples

33.1  Documents containing requirements for products, processes, services, persons, systems and bodies

All documents containing requirements for products, processes, services, persons, systems and bodies shall be written in accordance with the “neutrality principle”, such that conformity can be assessed by a manufacturer or supplier (first party), a user or purchaser (second party), or an independent body (third party).

Such documents shall not include requirements related to conformity assessment other than requirements which are necessary to provide repeatable and reproducible conformity assessment results.

Committees wishing to specify additional conformity assessment requirements for the product, process, service, persons, systems or bodies may only do so in a separate document or in a separate part of the document provided that the separate parts can be applied independently. Prior to commencing work on a separate document or separate part, a committee shall seek the approval of the ISO Committee on conformity assessment (ISO/CASCO) or IEC Standardization Management Board (IEC/SMB) or both as applicable.

For particular requirements in IEC, see the ISO/IEC Directives, Supplement – Procedures specific to IEC.

No document containing requirements for products, processes, services, persons, systems and bodies shall make conformity dependent on a quality management systems standard (i.e. it shall not, for example, make normative reference to ISO 9001).

33.2  Conformity assessment schemes and systems

Committees shall not develop documents providing general requirements for conformity assessment schemes and systems. Development of such documents is the responsibility of the ISO policy committee ISO/CASCO in liaison with the IEC Conformity Assessment Board (IEC/CAB).

Committees wishing

1. to propose the establishment of a conformity assessment scheme or system, or

2. to prepare documents specifying conformity assessment systems or schemes or sector-specific operating procedures for use by conformity assessment bodies and others for conformity assessment purposes,

shall consult with the secretariat of ISO/CASCO or IEC/CAB or both as appropriate, prior to commencement of the work to ensure that any documents developed are in line with the conformity assessment policies and rules approved by ISO/CASCO and IEC/CAB as relevant.

33.3  References to ISO/IEC conformity assessment documents

When a committee develops a document relating to conformity assessment systems or schemes, or any other document addressing conformity assessment aspects, the document shall make normative reference to the relevant published ISO/IEC documents for conformity assessment procedures, including ISO/IEC 17000 and ISO/IEC 17025. The committee may include verbatim text from the ISO/IEC documents for conformity assessment procedures but the committee shall not delete, change or interpret them. Committees shall consult with the ISO/CASCO or the IEC/CAB secretary or both, as appropriate, for advice on correctly referencing the ISO/IEC conformity assessment documents. Any request for addition, deletion, change or interpretation shall be submitted to the secretariats of ISO/CASCO and IEC/CAB for decision.