SIST EN ISO 17450-2:2013

SLOVENSKI STANDARD
SIST EN ISO 17450-2:2013
01-julij-2013
6SHFLILNDFLMDJHRPHWULMVNLKYHOLþLQL]GHOND6SORãQLSRJRMLGHO2VQRYQD
QDþHODVSHFLILNDFLMHSDUDPHWULLQQHJRWRYRVWL,62
Geometrical product specifications (GPS) - General concepts - Part 2: Basic tenets,
specifications, operators and uncertainties (ISO 17450-2:2012)
Geometrische Produktspezifikation und -prüfung (GPS) - Allgemeine Begriffe - Teil 2:
Grundlegende Lehrsätze, Spezifikationen, Operatoren und Unsicherheiten (ISO 17450-
2:2012)
Spécification géométrique des produits (GPS) - Concepts généraux - Partie 2: Principes
de base, spécifications, opérateurs et incertitudes (ISO 17450-2:2012)
Ta slovenski standard je istoveten z: EN ISO 17450-2:2012
ICS:
17.040.40 6SHFLILNDFLMDJHRPHWULMVNLK Geometrical Product
YHOLþLQL]GHOND*36 Specification (GPS)
SIST EN ISO 17450-2:2013 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 17450-2:2013

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SIST EN ISO 17450-2:2013


EUROPEAN STANDARD
EN ISO 17450-2

NORME EUROPÉENNE

EUROPÄISCHE NORM
October 2012
ICS 17.040.01
English Version
Geometrical product specifications (GPS) - General concepts -
Part 2: Basic tenets, specifications, operators, uncertainties and
ambiguities (ISO 17450-2:2012)
Spécification géométrique des produits (GPS) - Concepts Geometrische Produktspezifikation und -prüfung (GPS) -
généraux - Partie 2: Principes de base, spécifications, Allgemeine Begriffe - Teil 2: Grundlegende Lehrsätze,
opérateurs, incertitudes et ambiguïtés (ISO 17450-2:2012) Spezifikationen, Operatoren, Unsicherheiten und
Mehrdeutigkeiten (ISO 17450-2:2012)
This European Standard was approved by CEN on 15 September 2012.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 17450-2:2012: E
worldwide for CEN national Members.

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SIST EN ISO 17450-2:2013
EN ISO 17450-2:2012 (E)
Contents Page
Foreword .3

2

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SIST EN ISO 17450-2:2013
EN ISO 17450-2:2012 (E)
Foreword
This document (EN ISO 17450-2:2012) has been prepared by Technical Committee ISO/TC 213 "Dimensional
and geometrical product specifications and verification" in collaboration with Technical Committee
CEN/TC 290 “Dimensional and geometrical product specification and verification” the secretariat of which is
held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by April 2013, and conflicting national standards shall be withdrawn at the
latest by April 2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 17450-2:2012 has been approved by CEN as a EN ISO 17450-2:2012 without any
modification.

3

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SIST EN ISO 17450-2:2013
INTERNATIONAL ISO
STANDARD 17450-2
First edition
2012-10-01
Geometrical product specifications
(GPS) — General concepts —
Part 2:
Basic tenets, specifications, operators,
uncertainties and ambiguities
Spécification géométrique des produits (GPS) — Concepts
généraux — Partie 2: Principes de base, spécifications, opérateurs,
incertitudes et ambiguïtés
Reference number
ISO 17450-2:2012(E)
©
ISO 2012

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SIST EN ISO 17450-2:2013
ISO 17450-2:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
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Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved

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SIST EN ISO 17450-2:2013
ISO 17450-2:2012(E)
Contents Page
Foreword .iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Terms related to operations . 2
3.2 Terms related to operators . 3
3.3 Terms related to uncertainty . 7
3.4 Terms related to specifications . 9
4 Basic tenets . 11
5 Impact of uncertainty on basic tenets . 11
5.1 Impact of ambiguity of the description of the function and ambiguity of specification . 11
5.2 Impact of method and implementation uncertainties .12
6 Specification process .12
7 Verification process .13
Annex A (informative) Concept diagram.14
Annex B (informative) Drawing indications .15
Annex C (informative) Relationship to the GPS matrix model .16
Bibliography .18
© ISO 2012 – All rights reserved iii

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SIST EN ISO 17450-2:2013
ISO 17450-2:2012(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 17450-2 was prepared by Technical Committee ISO/TC 213, Dimensional and geometrical product
specifications and verification.
This first edition of ISO 17450-2 cancels and replaces ISO/TS 17450-2:2002, which has been technically
revised. It also incorporates ISO/TS 17450-2/Cor.1:2004.
ISO 17450 consists of the following parts, under the general title Geometrical product specifications (GPS) —
General concepts:
— Part 1: Model for geometrical specification and verification
— Part 2: Basic tenets, specifications, operators, uncertainties and ambiguities
iv © ISO 2012 – All rights reserved

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SIST EN ISO 17450-2:2013
ISO 17450-2:2012(E)
Introduction
This part of ISO 17450 is a Geometrical Product Specifications (GPS) standard and is to be regarded as a global
GPS standard (see ISO/TR 14638). It influences all chain links in all chains of standards in the general GPS matrix.
The ISO/GPS Masterplan given in ISO/TR 14638 gives an overview of the ISO/GPS system of which this
document is a part. The fundamental rules of ISO/GPS given in ISO 8015 apply to this document and the
default decision rules given in ISO 14253-1 apply to specifications made in accordance with this document,
unless otherwise indicated.
For more detailed information on the relationship of this part of ISO 17450 to other standards and to the GPS
matrix model, see Annex C.
This part of ISO 17450 covers several fundamental issues common to all the GPS standards developed by
ISO/TC 213 and, by presenting GPS’s basic tenets and specification and verification processes, explains some
of the underlying ideas and indicates the starting point for the standards developed by this technical committee.
It is pointed out that these ideas — and, for that matter, all the other ideas and concepts applied by ISO/TC 213
— are subject to development and refinement, as the TC’s recognition and understanding of them further
evolves during its ongoing standards work.
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SIST EN ISO 17450-2:2013
INTERNATIONAL STANDARD ISO 17450-2:2012(E)
Geometrical product specifications (GPS) — General concepts —
Part 2:
Basic tenets, specifications, operators, uncertainties and
ambiguities
1 Scope
This part of ISO 17450 defines terms related to specifications, operators (and operations) and uncertainties
used in geometrical product specifications (GPS) standards. It presents the basic tenets of the GPS philosophy
while discussing the impact of uncertainty on those tenets, and examines the processes of specification and
verification as they apply to GPS.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 14253-2:2011, Geometrical product specifications (GPS) — Inspection by measurement of workpieces
and measuring equipment — Part 2: Guidance for the estimation of uncertainty in GPS measurement, in
calibration of measuring equipment and in product verification
ISO 14660-1:1999, Geometrical Product Specifications (GPS) — Geometrical features — Part 1: General
terms and definitions
ISO 14978:2006, Geometrical product specifications (GPS) — General concepts and requirements for GPS
measuring equipment
ISO 17450-1:2011, Geometrical product specifications (GPS) — General concepts — Part 1: Model for
geometrical specification and verification
ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM:1995)
ISO/IEC Guide 99:2007, International vocabulary of metrology — Basic and general concepts and
associated terms (VIM)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 14253-2, ISO 14660-1, ISO 14978,
ISO 17450-1, ISO/IEC Guide 98-3, ISO/IEC Guide 99 and the following apply. See Figure A.1 for a concept
diagram giving an overview of the relationships between these terms; it is recommended that this figure be
consulted first.
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SIST EN ISO 17450-2:2013
ISO 17450-2:2012(E)
3.1 Terms related to operations
3.1.1
specification operation
operation formulated using mathematical expressions, geometrical expressions or algorithms, or a combination
of these, defining part of the specification
NOTE 1 Specification operations are used as part of a specification operator (3.2.3), in order to define a GPS
requirement for a work-piece (product or component).
NOTE 2 A specification operation is a theoretical concept.
EXAMPLE 1 Association of a minimum circumscribed cylinder in the specification of the diameter of a shaft.
EXAMPLE 2 Filtration by a Gaussian filter in the specification of a surface texture requirement.
3.1.2
default specification operation
specification operation (3.1.1) which is applied to a basic GPS specification (3.4.4) in the absence of any
additional information or modifier
NOTE 1 The default specification operation may be a global default (ISO default), company default or drawing default
specification operation.
NOTE 2 The default specification operation depends on the context in which the default specification operator is applied.
EXAMPLE 1 Evaluation of a two-point diameter in the specification of the diameter of a shaft using the default
indication 30 ± 0,1.
EXAMPLE 2 Filtration by a Gaussian filter (default filter) with the default cut-off length given in ISO 4288 in the
specification of Ra for a surface.
3.1.3
special specification operation
specification operation (3.1.1) which is applied to a basic GPS specification (3.4.4) to change or modify a default
specification operation (3.1.2) for this basic GPS specification with additional information or one or more modifiers
EXAMPLE 1 The association of a minimum circumscribed cylinder in the specification of the diameter of a shaft, when
the modifier symbol, , for envelope requirement, is used (see ISO 14405-1).
EXAMPLE 2 The filtration by a Gaussian filter (default filter) with a special cut-off length of 2,5 mm in the specification
of Ra for a surface, when the appropriate indication is used to override the default rules in ISO 4288.
3.1.4
actual specification operation
specification operation (3.1.1) which is indicated implicitly (in the case of a default specification operation)
or explicitly (in the case of a special specification operation) in a GPS requirement indicated in the technical
product documentation under consideration
NOTE An actual specification operation can be:
— indicated implicitly by an ISO basic GPS specification (3.4.4), or;
— indicated explicitly by a GPS specification element (3.4.1), or;
— omitted when the specification operator is not complete.
EXAMPLE 1 Evaluation of a two-point default diameter in an actual specification operation, such as when the
specification 30 ± 0,1 is used (see ISO 14405-1).
EXAMPLE 2 Filtration by a Gaussian filter (default filter) with a special cut-off length of 2,5 mm, and the calculation
of a surface texture requirement using the Ra algorithm, are two actual specification operations, when the specification
indicates Ra 1,5 with a 2,5 mm filter.
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SIST EN ISO 17450-2:2013
ISO 17450-2:2012(E)
3.1.5
verification operation
operation which is implemented in the form of a measurement, or by means of a measurement apparatus, or a
combination of these, which corresponds to an actual specification operation (3.1.4)
NOTE 1 Verification operations are used in the geometrical field of mechanical engineering to verify a product to the
corresponding specification operation (3.1.1).
NOTE 2 A verification operation is used to verify the requirements of a specification operation (3.1.1).
EXAMPLE 1 Evaluation of a two-point diameter when verifying the diameter of a shaft — using a micrometer, for instance.
EXAMPLE 2 Extraction of data points from a surface for surface finish verification using a nominal stylus tip radius of
2 µm and a sample spacing of 0,5 µm.
3.1.6
perfect verification operation
verification operation (3.1.5) which implements an ideal method of verifying an actual specification
operation (3.1.4) with no intentional deviation from its requirements
NOTE 1 Although the perfect verification operation implements an ideal method for verifying the specification operation,
and the method itself will introduce no measurement uncertainty; contributions to measurement uncertainty may still arise
from other sources, such as deficiencies, e.g. deviations of metrological characteristics, in the apparatus used.
NOTE 2 The purpose of calibration is generally to evaluate the magnitude of those measurement uncertainty
components originating from the measuring equipment.
EXAMPLE Extraction of data points from a surface using a nominal stylus tip radius of 2 µm and a sample spacing
of 0,5 µm during the verification of the surface finish, when this is the extraction operation indicated in the specification.
3.1.7
simplified verification operation
verification operation (3.1.5) with intentional deviations from the corresponding actual specification
operation (3.1.4)
NOTE These intentional deviations cause measurement uncertainty contributions in addition to the measurement
uncertainty contributions from the metrological characteristic deviation(s) in the implementation of the operation.
EXAMPLE The association of a two-point diameter in the verification of the size of a shaft — using a micrometer, for
instance — when the specification indicates that the minimum circumscribed cylinder association is to be used.
3.1.8
actual verification operation
verification operation (3.1.5) used in the actual measurement process
3.2 Terms related to operators
3.2.1
operator
ordered set of operations
3.2.2
functional operator
operator (3.2.1) with perfect correlation to the intended function of the workpiece/feature
NOTE 1 While a functional operator in most cases cannot formally be expressed as an ordered set of well-defined
operations, it can conceptually be thought of as a set of specification operation(s) (3.1.1) or verification operation(s)
(3.1.5) that would exactly describe the functional requirements of the workpiece.
NOTE 2 The functional operator is an idealized concept used, for comparison purposes only, to evaluate how well a
specification operator (3.2.3) or verification operator (3.2.9) expresses the functional requirements.
EXAMPLE Ability of a shaft to run in a hole with a seal for 2 000 h without leaking.
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SIST EN ISO 17450-2:2013
ISO 17450-2:2012(E)
3.2.3
specification operator
set of one or more specification operation(s) (3.1.1) applied in a specified order
NOTE 1 The specification operator is the result of the full interpretation of the combination of the GPS specification(s)
(3.4.3) indicated in the technical product documentation according to ISO GPS standards.
NOTE 2 A specification operator can be incomplete and could, in such a case, introduce ambiguity of specification (3.3.2).
NOTE 3 A specification operator is intended to define, for example, a specific possible “diameter” in a cylinder (two-
point diameter, minimum circumscribed circle diameter, maximum inscribed circle diameter, least squares circle diameter,
etc.), and not the generic concept “diameter”.
NOTE 4 The difference between the specification operator and the functional operator (3.2.2) causes ambiguity of
the description of the function (3.3.3).
EXAMPLE If the specification for a shaft were 30 h7 (see ISO 286-1 and ISO 14405-1), then the specification
operators for the upper and lower limits would be
— partition from the skin model of the non-ideal cylindrical surface;
— association of an ideal feature of type cylinder with the least squares criteria of association;
— construction of straight lines perpendicular to and intersecting the axis of the associated cylinder;
— extraction of two points for each straight line, where the line intersects the non-ideal cylindrical surface;
and
— evaluation of the distance between each set of two points, the largest distance being compared to the upper limit and
the smallest distance to the lower limit.
3.2.4
complete specification operator
specification operator (3.2.3) based on an ordered and complete set of fully defined specification
operation(s) (3.1.1)
NOTE A complete specification operator is unambiguous and therefore has no ambiguity of specification (3.3.2).
EXAMPLE 1 Specification of local diameter, defining how any distance between two opposite points is defined.
EXAMPLE 2 See the example in 3.2.3.
3.2.5
incomplete specification operator
specification operator (3.2.3) with one or more specification operation(s) (3.1.1) either missing, incompletely
defined or unordered, or any combination of these
NOTE 1 An incomplete specification operator is ambiguous and therefore introduces ambiguity of specification (3.3.2).
NOTE 2 In order to establish the corresponding verification operator (3.2.9), when an incomplete specification
operator is given, it is necessary to complete it by adding missing operations or missing parts of operation, or by ordering
the operations in the incomplete specification operator. See also method uncertainty (3.3.4).
EXAMPLE The specification of the step dimension 30 ± 0,1, which does not specify the association to be used.
3.2.6
default specification operator
specification operator (3.2.3) which is applied to a basic GPS specification (3.4.4) in the absence of any
additional information or modifiers
NOTE 1 The default specification operator can be:
— an ISO default specification operator defined by ISO standards, or;
— a national default specification operator defined by national standards, or;
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SIST EN ISO 17450-2:2013
ISO 17450-2:2012(E)
— a company default specification operator defined by company standards/documents, or;
— a drawing default specification operator defined on the drawing according to one of the above (see Annex B).
NOTE 2 A default specification operator can be either a complete specification operator (3.2.4) or an incomplete
specification operator (3.2.5).
EXAMPLE In accordance with ISO standards, the specification of Ra 1,5 indicates:
— partition from the skin model of a non-ideal surface;
— partition of non-ideal lines from this non-ideal surface in multiple places;
— extraction using the evaluation length and sample spacing given by the rules given in ISO 4288;
— filtration using a Gaussian filter with a cut-off wavelength and stylus tip radius given in ISO 4288;
and
— evaluation of Ra value as defined in ISO 4287 and ISO 4288 (16 % rule).
Since each of these operations is a default specification operation, and as they are used in the default order, the
specification operator (3.2.3) is a default specification operator.
3.2.7
special specification operator
specification operator (3.2.3) which is required when a special GPS specification (3.4.5) is used, including
one or more special specification operations (3.1.3).
NOTE 1 The special specification operator is defined by a GPS specification (3.4.3).
NOTE 2 A special specification operator may be a complete specification operator (3.2.4) or an incomplete
specification operator (3.2.5).
NOTE 3 A special specification operator can be established from a default operator by modifying one or more operations.
EXAMPLE 1 The specification for a shaft of 30 ± 0,1 is a special specification operator, because one of the
specification operations (3.1.1), the association of the minimum circumscribed cylinder, is not a default specification
operation (3.1.2).
EXAMPLE 2 The specification of Ra 1,5 using a 2,5 mm filter for a surface is a special specification operator, because
one of the specification operations (3.1.1), the cut-off length used in the filtration, is not a default specification
operation (3.1.2).
3.2.8
actual specification operator
specification operator (3.2.3) derived from an actual specification given in the technical product documentation
NOTE 1 The standard or standards in accordance with which the actual specification operator is to be interpreted are
identified explicitly or implicitly.
NOTE 2 An actual specification operator can be either a complete specification operator (3.2.4) or an incomplete
specification operator (3.2.5).
NOTE 3 An actual specification operator can be either a special specification operator (3.2.7) or a default
specification operator (3.2.6).
3.2.9
verification operator
ordered set of verification operation(s) (3.1.5)
NOTE 1 The verification operator is the metrological emulation of a specification operator (3.2.3) and is the basis for
the measurement procedure.
NOTE 2 A verification operator might not correspond perfectly to the specification operator. In this case, the differences
between the two result in a method uncertainty (3.3.4), which is part of the measurement uncertainty.
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SIST EN ISO 17450-2:2013
ISO 17450-2:2012(E)
EXAMPLE For an ISO basic specification for a local diameter, the implementation of the measurement with a
micrometer gives a type of verification operator.
3.2.10
perfect verification operator
verification operator (3.2.9) based on a complete set of perfect verification operation(s) (3.1.6) performed
in the prescribed order
NOTE 1 The only measurement uncertainty contributions from a perfect verification operator are from metrological
characteristic deviation(s) (see ISO 14978) in the implementation of the operator.
NOTE 2 The purpose of calibration is to evaluate the magnitude of these measurement uncertainty components
originating from the measuring equipment.
EXAMPLE In accordance with ISO standards, the verification of the specification Ra 1,5 is
— partition (choice) of the required surface from the actual workpiece,
— partition of non-ideal lines by the physical positioning of the measuring instrument in multiple places,
— extraction of data from the surface with an instrument in accordance with the requirements of ISO 3274, using the
evaluation length given in ISO 4288,
— filtration of data using a Gaussian filter with a cut-off wavelength determined by the rules in ISO 4288 and the
corresponding stylus tip radius and sample spacing,
— filtration of data using a Gaussian filter with a cut-off wavelength determined by the rules in ISO 4288,
— use of the styl
...