Geographic information - Encoding (ISO 19118:2011)

ISO 19118:2011 specifies the requirements for defining encoding rules for use for the interchange of data that conform to the geographic information in the set of International Standards known as the "ISO 19100 series".
ISO 19118:2011 specifies requirements for creating encoding rules based on UML schemas, requirements for creating encoding services, and requirements for XML-based encoding rules for neutral interchange of data.
ISO 19118:2011 does not specify any digital media, does not define any transfer services or transfer protocols, nor does it specify how to encode inline large images.

Geoinformation - Kodierung (ISO 19118:2011)

Diese Internationale Norm legt die Anforderungen an die Festlegung von Kodierungsregeln fest, die beim Austausch von Daten angewendet werden, die der Reihe von Internationalen Normen für Geoinformationen entsprechen.
Diese Internationale Norm legt Folgendes fest:
-   Anforderungen an die Erstellung von Kodierungsregeln auf der Basis von UML-Schemata;
-   Anforderungen an die Erstellung von Kodierungsdiensten;
-   Anforderungen an XML-basierte Kodierungsregeln für den neutralen Datenaustausch.
Diese Internationale Norm legt keine digitalen Medien fest, definiert keine Übertragungsdienste oder Über-tragungsprotokolle und enthält keine Festlegungen bezüglich der Kodierung von größeren Bildern inline.

Information géographique - Codage (ISO 19118:2011)

L'ISO 19118:2011 spécifie les exigences pour la définition des règles de codage à utiliser pour l'échange de données conformes à l'ensemble de Normes internationales relatives à l'information géographique connu sous le nom de «série ISO 19100».
L'ISO 19118:2011 spécifie les exigences de création des règles de codage basées sur les schémas UML, les exigences de création des services de codage, et les exigences en matière de règles de codage XML pour l'échange neutre de données.
L'ISO 19118:2011 ne spécifie pas les média numériques, ne définit aucun service de transfert ou de protocole de transfert, ni ne spécifie la façon d'encoder les grandes images en ligne.

Geografske informacije - Kodiranje (ISO 19118:2011)

Ta mednarodni standard določa zahteve za opredeljevanje pravil kodiranja za uporabo pri izmenjavi podatkov, ki so v skladu z geografskimi informacijami v setu mednarodnih standardov, znanih kot »serija ISO 19100«.
Ta mednarodni standard določa:
 zahteve za ustvarjanje pravil kodiranja na podlagi shem UML,
 zahteve za ustvarjanje pravil storitev kodiranja in
 zahteve za pravila kodiranja na osnovi XML za nevtralno izmenjavo podatkov.
Ta mednarodni standard ne določa digitalnih medijev, ne opredeljuje storitev prenosa ali protokolov prenosa in ne določa, kako se kodirajo velike slike znotraj vrstic.

General Information

Status
Withdrawn
Publication Date
30-Jan-2012
Withdrawal Date
29-Apr-2012
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Start Date
15-Oct-2011
Completion Date
15-Oct-2011

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SLOVENSKI STANDARD
SIST EN ISO 19118:2011
01-december-2011
1DGRPHãþD
SIST EN ISO 19118:2006
Geografske informacije - Kodiranje (ISO 19118:2011)
Geographic information - Encoding (ISO 19118:2011)
Geoinformation - Kodierung (ISO 19118:2011)
Information géographique - Codage (ISO 19118:2011)
Ta slovenski standard je istoveten z: EN ISO 19118:2011
ICS:
07.040 Astronomija. Geodezija. Astronomy. Geodesy.
Geografija Geography
35.240.70 Uporabniške rešitve IT v IT applications in science
znanosti
SIST EN ISO 19118:2011 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 19118:2011
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SIST EN ISO 19118:2011
EUROPEAN STANDARD
EN ISO 19118
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2011
ICS 35.240.70 Supersedes EN ISO 19118:2006
English Version
Geographic information - Encoding (ISO 19118:2011)

Information géographique - Codage (ISO 19118:2011) Geoinformation - Kodierung (ISO 19118:2011)

This European Standard was approved by CEN on 1 October 2011.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,

Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 19118:2011: E

worldwide for CEN national Members.
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SIST EN ISO 19118:2011
EN ISO 19118:2011 (E)
Contents Page

Foreword ..............................................................................................................................................................3

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SIST EN ISO 19118:2011
EN ISO 19118:2011 (E)
Foreword

This document (EN ISO 19118:2011) has been prepared by Technical Committee ISO/TC 211 "Geographic

information/Geomatics" in collaboration with Technical Committee CEN/TC 287 “Geographic Information” the

secretariat of which is held by BSI.

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 2012, and conflicting national standards shall be withdrawn at the

latest by April 2012.

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.

This document supersedes EN ISO 19118:2006.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following

countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech

Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,

Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,

Sweden, Switzerland and the United Kingdom.
Endorsement notice

The text of ISO 19118:2011 has been approved by CEN as a EN ISO 19118:2011 without any modification.

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SIST EN ISO 19118:2011
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SIST EN ISO 19118:2011
INTERNATIONAL ISO
STANDARD 19118
Second edition
2011-10-15
Geographic information — Encoding
Information géographique — Codage
Reference number
ISO 19118:2011(E)
ISO 2011
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SIST EN ISO 19118:2011
ISO 19118:2011(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2011

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
Case postale 56  CH-1211 Geneva 20
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 2011 – All rights reserved
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SIST EN ISO 19118:2011
ISO 19118:2011(E)
Contents Page

Foreword ............................................................................................................................................................ iv

Introduction ......................................................................................................................................................... v

1  Scope ...................................................................................................................................................... 1

2  Conformance ......................................................................................................................................... 1

2.1  Introduction ............................................................................................................................................ 1

2.2  Conformance classes related to encoding rules ............................................................................... 1

2.3  Conformance classes related to encoding services ......................................................................... 1

3  Normative references ............................................................................................................................ 2

4  Terms and definitions ........................................................................................................................... 2

5  Symbols and abbreviated terms .......................................................................................................... 6

6  Fundamental concepts and assumptions ........................................................................................... 7

6.1  Concepts ................................................................................................................................................ 7

6.2  Data interchange ................................................................................................................................... 7

6.3  Application schema ............................................................................................................................... 8

6.4  Encoding rule ......................................................................................................................................... 9

6.5  Encoding service ................................................................................................................................. 10

6.6  Transfer service ................................................................................................................................... 10

7  Character repertoire ............................................................................................................................ 11

8  Generic instance model ...................................................................................................................... 11

8.1  Introduction .......................................................................................................................................... 11

8.2  Relation between UML and the instance model ............................................................................... 14

9  Encoding rules ..................................................................................................................................... 14

9.1  Introduction .......................................................................................................................................... 14

9.2  General encoding requirements ........................................................................................................ 15

9.3  Input data structure ............................................................................................................................. 17

9.4  Output data structure .......................................................................................................................... 17

9.5  Conversion rules ................................................................................................................................. 18

9.6  Examples .............................................................................................................................................. 18

10  Encoding service ................................................................................................................................. 18

Annex A (normative) XML-based encoding rule ............................................................................................ 20

Annex B (normative) Abstract test suit .......................................................................................................... 21

Annex C (informative) XML-based encoding rule in use by communities .................................................. 25

Bibliography ...................................................................................................................................................... 68

© ISO 2011 – All rights reserved iii
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SIST EN ISO 19118:2011
ISO 19118:2011(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 19118 was prepared by Technical Committee ISO/TC 211, Geographic information/Geomatics.

This second edition cancels and replaces the first edition (ISO 19118:2005), which has been technically

revised.
iv © ISO 2011 – All rights reserved
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SIST EN ISO 19118:2011
ISO 19118:2011(E)
Introduction

This International Standard specifies the requirements for defining encoding rules used for interchange of

geographic data within the set of International Standards known as the “ISO 19100 series”. An encoding rule

allows geographic information defined by application schemas and standardized schemas to be coded into a

system-independent data structure suitable for transport and storage. The encoding rule specifies the types of

data being coded and the syntax, structure and coding schemes used in the resulting data structure. The

resulting data structure can be stored on digital media or transferred using transfer protocols. It is intended

that the data be read and interpreted by computers, but data can be in a form that is human readable.

The choice of one encoding rule for application-independent data interchange does not exclude application

domains and individual nations from defining and using their own encoding rules that can be platform

dependent or more effective with regard to data size or processing complexity. XML is a subset of

ISO/IEC 8879 and has been chosen because it is independent of computing platform and interoperable with

the World Wide Web.

This International Standard is divided into three logical sections. The requirements for creating encoding rules

based on UML schemas are specified in Clauses 6 to 9. The requirements for creating encoding service are

specified in Clause 10, and the requirements for XML-based encoding rules are specified in Annex A.

The XML-based encoding rule is intended for use as a neutral data interchange. It relies on the Extensible

Markup Language (XML) and the ISO/IEC 10646 character set standards.

The geographic information standards are organized within the set of International Standards known as the

“ISO 19100 series”. The background and the overall structure of this series of International Standards and the

fundamental description techniques are defined in ISO 19101, ISO/TS 19103 and ISO/TS 19104.

Users of this International Standard can develop application schemas to formally describe geographic

information. An application schema is compiled by integrating elements from other standardized conceptual

schemas (e.g. ISO 19107). How this integration takes place is described in ISO 19109. The set of

International Standards known as the “ISO 19100 series” also defines a set of common services that are

available when developing geographic information applications. The common services are generally defined in

ISO 19119 and cover access to, and processing of, geographic information according to the common

information model. This International Standard covers implementation issues.
© ISO 2011 – All rights reserved v
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SIST EN ISO 19118:2011
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SIST EN ISO 19118:2011
INTERNATIONAL STANDARD ISO 19118:2011(E)
Geographic information — Encoding
1 Scope

This International Standard specifies the requirements for defining encoding rules for use for the interchange

of data that conform to the geographic information in the set of International Standards known as the

“ISO 19100 series”.
This International Standard specifies
 requirements for creating encoding rules based on UML schemas,
 requirements for creating encoding services, and
 requirements for XML-based encoding rules for neutral interchange of data.

This International Standard does not specify any digital media, does not define any transfer services or

transfer protocols, nor does it specify how to encode inline large images.
2 Conformance
2.1 Introduction
Two sets of conformance classes are defined for this International Standard.
2.2 Conformance classes related to encoding rules

All encoding rules shall pass all test cases of the abstract test suite in B.1. All encoding rules shall pass all test

cases of the abstract test suite in B.2 and/or B.3.
Table 1 — Conformance classes related to encoding rules
Subclause of the
Conformance class
abstract test suite
All encoding rules B.1
Encoding rule with instance conversion B.2
Encoding rule with schema conversion B.3
2.3 Conformance classes related to encoding services

All encoding services shall pass all test cases of the abstract test suite in B.4. Depending on the capabilities of

the encoding service, it shall pass all test cases of additional conformance classes in accordance with Table 2.

© ISO 2011 – All rights reserved 1
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SIST EN ISO 19118:2011
ISO 19118:2011(E)
Table 2 — Conformance classes related to encoding services
Subclause of the
Conformance class
abstract test suite
All encoding services B.4
Generic encoding service B.5
Service that encodes data B.6
Service that decodes data B.7
Service that generates an output data structure schema B.8
3 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 8601:2004, Data elements and interchange formats — Information interchange — Representation of

dates and times
ISO/IEC 10646:2011, Information technology — Universal Coded Character Set (UCS)
ISO/TS 19103:2005, Geographic information — Conceptual schema language
ISO 19109:2005, Geographic information — Rules for application schema
Extensible Markup Language (XML) 1.0, W3C Recommendation. Available at

4 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
4.1
application schema
conceptual schema (4.5) for data (4.8) required by one or more applications
[ISO 19101:2002, 4.2]

NOTE An application schema describes the content, the structure and the constraints applicable to information

(4.22) in a specific application domain.
4.2
character

member of a set of elements that is used for the representation, organization, or control of data (4.8)

[ISO/IEC 2382-1:1993, 01.02.11]
4.3
code
representation of a label according to a specified scheme
2 © ISO 2011 – All rights reserved
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SIST EN ISO 19118:2011
ISO 19118:2011(E)
4.4
conceptual model
model (4.27) that defines concepts of a universe of discourse (4.33)
[ISO 19101:2002, 4.4]
4.5
conceptual schema
formal description of a conceptual model (4.4)
[ISO 19101:2002, 4.5]
4.6
conceptual schema language

formal language based on a conceptual formalism for the purpose of representing conceptual schemas (4.5)

[ISO 19101:2002, 4.6]
EXAMPLES UML, EXPRESS, IDEF1X.
NOTE A conceptual schema language may be lexical or graphical.
4.7
conversion rule

rule for converting instances in the input data (4.8) structure to instances in the output data structure

4.8
data

reinterpretable representation of information (4.22) in a formalized manner suitable for communication,

interpretation, or processing
[ISO/IEC 2382-1:1993, 01.01.02]
4.9
data interchange
delivery, receipt and interpretation of data (4.8)
4.10
data transfer
movement of data (4.8) from one point to another over a medium (4.26)
NOTE Transfer of information (4.22) implies transfer of data.
4.11
data type

specification of a value domain (4.34) with operations allowed on values in this domain

[ISO/TS 19103:2005, 4.1.5]
EXAMPLES Integer, Real, Boolean, String and Date.

NOTE A data type is identified by a term, e.g. Integer. Values of the data types are of the specified value domain, e.g.

all integer numbers between –65537 and 65536. The set of operations can be +, -, * and / and is semantically well defined.

A data type can be simple or complex. A simple data type defines a value domain where values are considered atomic in

a certain context, e.g. Integer. A complex data type is a collection of data types that are grouped together. A complex data

type may represent an object and can, thus, have identity.
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SIST EN ISO 19118:2011
ISO 19118:2011(E)
4.12
dataset
identifiable collection of data (4.8)
[ISO 19115:2003, 4.2]
4.13
encoding
conversion of data (4.8) into a series of codes (4.3)
4.14
encoding rule

identifiable collection of conversion rules (4.7) that define the encoding (4.13) for a particular data (4.8)

structure
EXAMPLES XML, ISO 10303-21, ISO/IEC 8211.

NOTE An encoding rule specifies the types of data being converted as well as the syntax, structure and codes (4.3)

used in the resulting data structure.
4.15
encoding service
software component that has an encoding rule (4.14) implemented
4.16
feature
abstraction of real world phenomena
[ISO 19101:2002, 4.11]

NOTE A feature may occur as a type or an instance. Feature type or feature instance is used when only one is meant.

4.17
file
named set of records stored or processed as a unit
[ISO/IEC 2382-1:1993, 01.08.06]
4.18
geographic data

data (4.8) with implicit or explicit reference to a location relative to the Earth

[ISO 19109:2005, 4.12]
4.19
geographic information

information (4.22) concerning phenomena implicitly or explicitly associated with a location relative to the

Earth
[ISO 19101:2002, 4.16]
4.20
identifier

linguistically independent sequence of characters (4.2) capable of uniquely and permanently identifying that

with which it is associated
[ISO 19135:2005, 4.1.5]
4 © ISO 2011 – All rights reserved
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SIST EN ISO 19118:2011
ISO 19118:2011(E)
4.21
identification convention
set of rules for creating identifiers (4.20)
4.22
information

knowledge concerning objects, such as facts, events, things, processes, or ideas, including concepts, that

within a certain context has a particular meaning
[ISO/IEC 2382-1:1993, 01.01.01]
4.23
instance model

representation model (4.27) for storing data (4.8) according to an application schema (4.1)

4.24
interface
UML named set of operations that characterize the behaviour of an element
[ISO/IEC 19501]
4.25
interoperability

capability to communicate, execute programs, or transfer data (4.8) among various functional units in a

manner that requires the user to have little or no knowledge of the unique characteristics of those units

[ISO/IEC 2382-1:1993, 01.01.47]
4.26
medium
substance or agency for storing or transmitting data (4.8)
[1]
EXAMPLES Compact disc, internet , radio waves, etc.
4.27
model
abstraction of some aspects of reality
[ISO 19109:2005, 4.14]
4.28
schema
formal description of a model (4.27)
[ISO 19101:2002, 4.25]
4.29
schema model
representation model (4.27) for storing schemas (4.28)
EXAMPLE Representation model for a schema repository.
4.30
stereotype
UML new type of modelling element that extends the semantics of the metamodel
[ISO/IEC 19501]
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SIST EN ISO 19118:2011
ISO 19118:2011(E)

NOTE It is necessary that stereotypes be based on certain existing types or classes in the metamodel. Stereotypes

may extend the semantics, but not the structure, of pre-existing types and classes. Certain stereotypes are predefined in

the UML, others may be user-defined. Stereotypes are one of three extensibility mechanisms in UML; the others are

constraint and tagged value.
4.31
transfer protocol
common set of rules for defining interactions between distributed systems
4.32
transfer unit
collection of data (4.8) for the purpose of a data transfer (4.10)
NOTE A transfer unit does not have to be identifiable like a dataset (4.12).
4.33
universe of discourse
view of the real or hypothetical world that includes everything of interest
[ISO 19101:2002, 4.29]
4.34
value domain
set of accepted values
[ISO/TS 19103:2005, 4.1.15]

EXAMPLE The range 3-28, all integers, any character, enumeration of all accepted values (green, blue, white).

5 Symbols and abbreviated terms
DCE Distributed computing environment
DUID Domain unique identifier
HTML Hypertext markup language
MODIS Moderate resolution imaging spectroradiometer
POSC Petroleum Open Standards Consortium
TIFF Tagged image file format
UCS Universal multiple-octet coded character set
UML Unified modelling language
UTF UCS Transfer format
UUID Universally unique identifier
XML Extensible markup language
6 © ISO 2011 – All rights reserved
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SIST EN ISO 19118:2011
ISO 19118:2011(E)
6 Fundamental concepts and assumptions
6.1 Concepts

The purpose of the set of International Standards known as the “ISO 19100 series” is to enable interoperability

between heterogeneous geographic information systems. To achieve interoperability between heterogeneous

systems, it is necessary to determine two fundamental issues. The first issue is to define the semantics of the

content and the logical structures of geographic data. This shall be done in an application schema. The

second issue is to define a system- and platform-independent data structure that can represent data

corresponding to the application schema.

The fundamental concepts of data interchange, i.e. the procedure based on the application schema for

encoding, delivery, receipt and interpretation of geographic data, are described in 6.2 to 6.6. An overview of

the data interchange process is described in 6.2; 6.3 introduces application schemas that allow interpretation

of geographic data; 6.4 describes the importance of the encoding rule for producing system-independent data

structures; 6.5 describes a software component, called the encoding service, for executing the encoding rule;

and 6.6 describes the procedure for delivery and receipt, called the transfer service.

6.2 Data interchange

An overview of a data interchange is shown in Figure 1. System A wants to send a dataset to system B. To

ensure a successful interchange, it is necessary that A and B decide on three things: i.e. a common

application schema I, which encoding rule R to apply, and what kind of transfer protocol to use. The

application schema is the basis of a successful data transfer and defines the possible content and structure of

the transferred data, whereas the encoding rule defines the conversion rules for how to code the data into a

system-independent data structure.
System A System B
Application
schema
Internal Internal
schema schema
A B
Internal Internal
i i
M M
A B
AI IB
database database
Encoding
Encoding
service
service
(Decoding)
File Transfer Transfer File
system services services system
Defines
Data transfer
Data flow
System boundary System boundary
Figure 1 — Overview of data interchange between two systems
© ISO 2011 – All rights reserved 7
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SIST EN ISO 19118:2011
ISO 19118:2011(E)

Both systems, A and B, store data in an internal database according to an internal schema, but the schemas

are usually different, i.e. schema A is not equal to schema B. It is necessary to take the following logical steps

in order to transfer a dataset from A's internal database to B's internal database.

a) The first step for system A is to translate its internal data into a data structure that is in accordance with

the common application schema I. Here, this is done by defining a mapping from the concepts of the

internal schema to the concepts defined in the application schema and by writing appropriate mapping

software to translate the data instances. In Figure 1, this mapping is denoted as M . The result is an

application-schema-specific data structure, i . The data structure is stored in memory or on an

intermediate file and is system-dependent and, thus, is not suitable for transfer.

b) The next step is to use an encoding service, which applies the encoding rule R to create a data structure

that is system independent and, therefore, suitable for transfer. This encoded dataset is called d and may

be stored in a file system or transferred using a transfer service.

c) System A then invokes a transfer service to send the encoded dataset d to system B. The transfer service

follows a transfer protocol for how to do packaging and how the actual transportation over an on-line or

off-line communication medium should take place. It is necessary that both parties agree on the transfer

protocol used.

d) The transfer service on system B receives the transferred dataset, and according to the protocol the

dataset is unpacked and stored as an encoded dataset d, e.g. on an intermediate file.

e) In order to get an application-schema-specific data structure i , system B applies the inverse encoding

rule R to interpret the encoded data.

f) To use the dataset, it is necessary that B translate the application-schema-specific data structure i into

its internal database. This is done by defining a mapping from the application schema into its internal

schema and by writing software that does the actual translation. In Figure 1 this mapping is denoted M .

This International Standard specifies only the requirements for creating encoding rules and the encoding

services and not the whole data interchange process. Thus, only steps b) and e) are standardized. Steps a),

c), d) and f) use general information technology services.
6.3 Application schema

An application schema is a conceptual schema for applications with similar data requirements. The application

schema i
...

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