ISO 20616-1:2021

INTERNATIONAL ISO
STANDARD 20616-1
First edition
2021-09
Graphic technology — File format for
quality control and metadata —
Part 1:
Print requirements eXchange (PRX)
Technologie graphique — Format de fichier pour le contrôle qualité
et les métadonnées —
Partie 1: Print requirements eXchange (PRX)
Reference number
ISO 20616-1:2021(E)
©
ISO 2021

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ISO 20616-1:2021(E)

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© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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ISO 20616-1:2021(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Documentation conventions . 2
5 Requirements . 3
5.1 General . 3
5.2 Extensibility . 3
5.2.1 General. 3
5.2.2 TagCollection . 3
5.2.3 CustomResources . 3
5.3 Employing CxF . 3
5.4 PRX quality specification . 4
5.4.1 Overview . 4
5.4.2 PRX element . 4
5.4.3 PRXInfo element . . 4
5.4.4 BuyerInfo element . 5
5.4.5 EvaluationInfo element . 5
5.4.6 PercentAcceptableScores element . 5
5.4.7 GradingInfo element . 6
5.4.8 GradingScale element . 6
5.4.9 Grade element . 6
5.4.10 ValueRange element. 6
5.4.11 ZeroBaseline element . 7
5.4.12 BasisOfCalculation element . 7
5.4.13 MinimumAcceptableRank element . 8
5.4.14 DesiredRank element . . . 8
5.4.15 QualitySpecification element . 8
5.4.16 CustomerJob element . 8
5.4.17 CustomerItem element . 9
5.4.18 ItemDescription element . 9
5.4.19 InkGuidelines element .10
5.4.20 QualityGoals element .10
5.4.21 ComplianceGoal element .10
5.4.22 CalculationVariable element .11
5.4.23 GradeWeightingFactor element .11
5.4.24 ScoringInfo element .11
5.4.25 ScoreWeightingFactor element .11
5.4.26 ParameterName element .11
5.4.27 CustomerItemIdLink element .11
5.4.28 SamplingPosition element .11
5.4.29 SamplingPositionImageIdLink element.11
5.4.30 SamplingPositionMatrix element .12
5.4.31 Color element .12
5.4.32 Registration element .13
5.4.33 Defects element.14
5.4.34 Barcode element .14
5.4.35 CxFReferenceData element .15
5.4.36 SamplingPositionImageData element .15
5.4.37 PositionLocationImage element .15
5.4.38 TagCollection element .15
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ISO 20616-1:2021(E)

5.4.39 CustomResources element .15
5.4.40 PRX simple types .15
Annex A (normative) ISO 20616-1 XML schema .24
Annex B (informative) PRX principles and concepts .25
Annex C (informative) Samples .27
Bibliography .30
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ISO 20616-1:2021(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 130, Graphic technology.
A list of all parts in the ISO 20616 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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ISO 20616-1:2021(E)

Introduction
The ISO 20616 series defines standard XML schemas designed to enable the digital exchange of print
quality data and metadata between trading partners within the graphic arts supply chain. In the
past, a number of different non-standard data formats have been used to communicate print quality
metrics. It is a general observation that many of these existing non-standard data formats describe
similar types of information. Existing standard data formats cover either too much or too little scope
to address industry requirements. Hence, there is an industry need for a single, standard, concise set of
data formats for the communication of print quality.
Each part of the ISO 20616 series is intended to stand alone, but may be used together, if that option is
chosen. The goal of ISO 20616 is to maintain the degree of flexibility required by print buyers for all
kinds of print generated for all purposes from any print device while minimizing the uncertainty of the
data exchanged.
ISO 20616-1, PRX, is intended to facilitate the one-way digital transmission of customer expectations
(i.e. print quality requirements) for a print job or class of print jobs, from a print buyer to print service
providers and other relevant stakeholders. PRX is not designed for ordering print jobs, but rather to
establish a buyer’s policy for expected quality. PRX is designed to enable the print buyer to specify
references, tolerances, scoring/grading scales and the mathematical formula to be employed by the
print buyer to assess the quality of their printed materials. PRX may also be used communicate a print
buyer’s compliance requirements.
Some portions of ISO 20616-1 are available as electronic files found at https:// standards .iso .org/ iso/
20616/ -1/ ed -1/ en/ :
— ISO-TC130_N4211_CD__20616-1_3_Electronic_Files.zip (all 20616-1 support documents);
— ISO20616-1prx.xsd;
— ISO20616-1prx_lines.pdf (printable PRX schema with reference lines numbered);
— ISO20616-1SchemaDoc.pdf (detailed schema documentation with graphics);
— PRX_MasterSampleA.pdf (printable sample with reference lines numbered);
— PRX_MasterSampleA.prx (parsable sample);
— PRX_MasterSampleB.pdf (printable sample with reference lines numbered);
— PRX_MasterSampleB.prx (parsable sample);
— PRX_MasterSampleC.pdf (printable sample with reference lines numbered);
— PRX_MasterSampleC.prx (parsable sample).
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INTERNATIONAL STANDARD ISO 20616-1:2021(E)
Graphic technology — File format for quality control and
metadata —
Part 1:
Print requirements eXchange (PRX)
1 Scope
This document specifies an extensible file format in conformity with W3C Extensible Markup Language
(XML) 1.0, for the exchange of print quality requirements data and metadata between print quality
control applications including, but not limited to, print quality management systems.
This document is not intended for automating the loading of print requirement goals into the quality
control systems employed by print quality service providers.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 17972-3, Graphic technology — Colour data exchange format (CxF/X) — Part 3: Output target data
(CxF/X-3)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
basis of calculation
formula by which print quality is calculated by the print buyer (3.3)
3.2
grade
print buyer's (3.3) evaluation of the overall level of print quality for a printed item
3.3
print buyer
name of the customer or entity purchasing printing services and products
3.4
rank
integer value assigned to a print quality grade (3.2) or score (3.5) based on a scale of zero or more,
where the higher the integer, the better the print quality
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ISO 20616-1:2021(E)

3.5
score
print buyer's (3.3) evaluation of the quality for a single quality parameter such as colour or defects
3.6
XML
Extensible Markup Language
set of rules recommended by the World Wide Web Consortium (W3C) for encoding documents in a
digital format which is both human-readable and machine-readable
3.7
XML attribute
attribute
XML construct included within the start tag of an XML element that modifies, or provides descriptive
metadata about, that element’s content
3.8
XML element
element
data structure including a start tag, an end tag, data between these tags, and, possibly, a set of XML
attributes
[SOURCE: ISO 13584-32:2010, 3.22, modified — Added admitted term.]
3.9
XML root element
root element
single XML element that encloses all the other elements and is therefore the sole parent element to all
the other elements
3.10
XML schema
language for describing the structure and constraining the contents of XML documents
[SOURCE: ISO 25720:2009, 4.32]
3.11
XML schema parser
application that is capable of validating document schemes (content and structure) and descriptor data
types against their schema definition
4 Documentation conventions
The following documentation conventions are used.
— Names of XML elements are shown in bold type; for example, BuyerInfo.
— Names of XML attributes are shown in italics; for example, @DisplayName.
— Names of XML datatypes are shown in italics; for example, originType.
XML XPaths are used to identify XML elements. For example, BuyerInfo/ParentCompany refers to an
element (ParentCompany) that is a child of another element (BuyerInfo).
Similarly, XML XPaths are used to refer to XML attributes. For example, CustomerItem/@Id refers to
an attribute (Id) of an element (CustomerItem).
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ISO 20616-1:2021(E)

5 Requirements
5.1 General
The following general requirements shall be met when using PRX XML to exchange print quality data
and metadata:
— PRX print quality requirements data should be validated using an XML schema parser employing
the ISO 20616-1 XML schema, ISO20616-1PRX.xsd.
— If PRX quality requirements data is exchanged as a standalone file, the file extension shall be ".prx".
— The root element of ISO 20616-1 print quality requirements data shall be a single PRX element.
— A valid PRX element shall contain the required namespace information in the root element: ( xmlns:p rx = "https:// idealliance .org/ prx">) followed by the XML elements and XML attributes
specified by the ISO 20616-1 XML schema, ISO20616-1PRX.xsd.
— If colour quality reference data is being exchanged, the PRX root element shall contain the required
namespace information for CxF, "xmlns: cc = http:// colorexchangeformat .com/ CxF3 -core".
5.2 Extensibility
5.2.1 General
To provide for extensibility in the PRX model, the specification includes two blocks modelled directly
from the extensibility provided by CxF; TagCollection and CustomResources.
5.2.2 TagCollection
TagCollection may only be used to insert additional application-specific XML print quality
requirements child elements into a PRX data structure at the agreement of all trading partners. Use of
TagCollection is highly discouraged.
5.2.3 CustomResources
CustomResources may only be used to insert additional application-specific XML print quality
requirements data models into a PRX data structure at the agreement of all trading partners. Use of
CustomResources is highly discouraged.
5.3 Employing CxF
ISO 17972-1 shall be used to exchange print quality colour data and metadata. The following
requirements shall be met when using CxF to exchange print quality colour requirements data and
metadata.
— Only Core CxF data shall be employed as the data store for colour requirements data.
— CxF shall be employed as a complete CxF hierarchy.
NOTE Retaining < c c: C x F > as the root element ensures direct importability from colour measurement
devices.
— CxF should only be used to customize CxF if specified by a business agreement among
trading partners.
— CxF should only be used to customize CxF if specified by a business
agreement among trading partners.
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ISO 20616-1:2021(E)

— CxF and should only
be used to customize CxF if specified by a business agreement among trading partners.
— Non-appropriate CxF elements (listed above) may be written into a PRX data, but should only be
processed by receiving systems if specified by a business agreement among trading partners.
5.4 PRX quality specification
5.4.1 Overview
The ISO20616-1PRX schema provides the rules for the order, occurrence and datatypes for the fields
that make up a print-quality requirements exchange. The PRX schema is the immutable specification.
Annex A, a PDF version of the schema printed with reference line numbers, shall be used to provide a
line number reference for each element documented in this subclause. Additional requirements that
cannot be specified by an XML schema are found in the following subclauses.
NOTE The spelling of fields in PRX were designed to match the spelling of fields taken from ISO 17972-3. A
specific example is the use of the word "color" instead of "colour".
See Annex B for documentation about the principles and concepts underlying the design and usage of
this document. See Annex C for usage samples to help guide implementing this document.
5.4.2 PRX element
The PRX element is the root element of a print quality requirements data exchange. The PRX element
shall be used to specify a print buyer’s print quality requirements. The PRX element shall conform to
the rules specified by ISO20616-1PRX.xsd (lines 12 to 30). See Table 1.
Table 1 — PRX fields
Field name Normative description
PRXInfo See 5.4.3 PRXInfo element.
BuyerInfo See 5.4.4 BuyerInfo element.
EvaluationInfo See 5.4.5 EvaluationInfo element.
QualitySpecification See 5.4.15 QualitySpecification element.
CxFReferenceData See 5.4.34 CxFReferenceData element.
SamplingPositionImageData See 5.4.35 SamplingPositionImageData element.
5.4.3 PRXInfo element
5.4.3.1 General
The PRXInfo element shall be used to identify the instance of print quality requirements being
exchanged. The PRXInfo element shall conform to the rules specified by ISO20616-1PRX.xsd (lines 35
to 47). The PRXInfo element is made up of elements described in 5.4.3.2 to 5.4.3.4.
5.4.3.2 PRXDate element
The PRXDate element shall be used to identify date or date/time this PRX data was generated. The
PRXDate element element shall conform to the rules specified by ISO20616-1PRX.xsd (lines 51 to 55).
5.4.3.3 PRXId element
The PRXId element shall be used to provide an identifier (unique in the context of system generated
identifiers assigned on the specified PRXDate) for this print quality requirements specification. The
PRXId element shall conform to the rules specified by ISO20616-1PRX.xsd (lines 59 to 63).
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ISO 20616-1:2021(E)

5.4.3.4 PRXSoftware-Version
PRXSoftware-Version shall be used to identify the software and version that generated this PRX file.
PRXId element shall conform to the rules specified by ISO20616-1PRX.xsd (lines 67 to 71)
NOTE Concatenation of the PRXDate, PRXId and PRXSoftware-Version make up a unique identifier for
this print quality data report.
5.4.4 BuyerInfo element
5.4.4.1 General
The BuyerInfo element shall be used to identify the business entity buying print and specifying print
quality requirements. The BuyerInfo element shall conform to the rules specified by ISO20616-1PRX.xsd
(lines 76 to 89). The BuyerInfo element is made up of elements described in 5.4.4.2 to 5.4.4.5.
5.4.4.2 ParentCompany element
The ParentCompany element shall be used to identify the company that controls an entity such as a
print buyer. The ParentCompany element shall conform to the rules specified by ISO20616-1PRX.xsd
(lines 93 to 97).
5.4.4.3 CompanyName element
The CompanyName element shall be used to identify the print buyer’s business entity. The
CompanyName element shall conform to the rules specified by ISO20616-1PRX.xsd (lines 101 to 105).
5.4.4.4 LocationDesignator
The LocationDesignator element shall be used to provide a designation for the location of a company
or party as a second level of identification for that company or party. The LocationDesignator element
shall conform to the rules specified by ISO20616-1PRX.xsd (lines 109 to 113).
NOTE LocationDesignator can be a unique identifier, city/state/country designation, postal code,
geographic coordinates or simply be a designator code employed by the print buyer. This element is purposefully
flexible to facilitate broad print buyer adoption.
5.4.4.5 ContactDesignator
The ContactDesignator element shall be used to provide a designation for information required to
communicate with a business entity. The ContactDesignator element shall conform to the rules
specified by ISO20616-1PRX.xsd (lines 117 to 121).
NOTE ContactDesignator can be email, street address, phone, fax, etc. or simply be a designator code
employed by the print buyer. This element is purposefully flexible to facilitate broad print buyer adoption.
5.4.5 EvaluationInfo element
The EvaluationInfo element shall be used to provide information about the evaluation method that
the print buyer intends to use. The EvaluationInfo element shall conform to the rules specified by the
ISO20616-1PRX.xsd (lines 227 to 238). The EvaluationInfo element is made up of elements described
in 5.4.6 to 5.4.7.
5.4.6 PercentAcceptableScores element
The PercentAcceptableScores element shall be used to provide the calculated percent of
all scored parameters that shall be within the print buyers acceptable scoring range. The
PercentAcceptableScores element shall conform to the rules specified by ISO20616-1PRX.xsd (lines
389 to 393).
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ISO 20616-1:2021(E)

5.4.7 GradingInfo element
The GradingInfo element shall be used to provide grading criteria that the print buyer intends to use
to evaluate overall print quality as a formal grade. The GradingInfo element shall be as specified by the
ISO20616-1PRX.xsd (lines 242 to 255). The GradingInfo element is made up of elements described in
5.4.8 to 5.4.14.
5.4.8 GradingScale element
The GradingScale element shall be used to provide the print buyer’s method to assign grades for
overall print quality. The GradingScale element shall be as specified by the ISO20616-1PRX.xsd (lines
446 to 457). The GradingScale element is made up of elements described in 5.4.9 to 5.4.11.
5.4.9 Grade element
The Grade element shall be used to provide the print buyer’s indicator for the overall print quality of a
printed item. The Grade element shall be as specified by the ISO20616-1PRX.xsd (lines 461 to 473).
...