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• DataType A descriptor of a set of values that lack identity independent existence and the possibility of side effects. A DataType is a class with no
operations whose primary purpose is to hold the information. • CodeList A flexible enumeration that uses string values for expressing a list
of potential values. If the list alternatives are completely known, an enumeration shall be used; if the only likely alternatives are known, a code list shall be used.
• Enumeration A data type whose instances form a list of alternative literal values. Enumeration means a short list of well-understood potential values within
a class. In this document, the following standard data types are used:
• CharacterString – A sequence of characters • Boolean – A value specifying TRUE or FALSE
• Integer – An integer number • Identifier – Unique identifier of an object
• URI – An identifier of a resource that provides more information • URL – An identifier of an on-line resource that can be electronically accessed
5.3 Document terms and definitions
This document uses the specification terms defined in Subclause 5.3 of [OGC 05-008c1].
6 System context
This section focuses on the purpose, scope and policies of catalogue services that comply with the given profile. It documents special requirements and describes the context of
use.
6.1 Application domain
A metadata repository managed by a catalogue implementing this application profile deals with metadata about geospatial data, geospatial services and geospatial applications.
It is intentional that the profile specified in this document does not attempt to specify a general-purpose catalogue. Rather, it allows the retrieval and management of the
metadata objects referred to above.
This application profile has no specific disciplinary focus. All communities working with these sorts of geospatial information are addressed. Typical communities are surveying,
environment, geology, landscaping, water management, power industry, telecommunications etc.
Copyright © 2007 Open Geospatial Consortium, Inc. All Rights Reserved. 29
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The intention is to implement a generally understood information model based on standard metadata with only a few relationships among the catalogue items. Usage should
be as simple as possible, implementing a set of use cases typical in the geospatial community.
The requirements of the information model, search properties, details of the results sets and interfaces were defined in close cooperation with users in various communities as
well as software vendors.
This profile allows for a catalogue to accept a request from a client and distribute the request to one or more other catalogues within a federation. In this case, the metadata
entries managed by the other catalogues become available to their own clients. It is possible to start a search from only one known location and to search as many catalogues
as possible with the same set of attributes.
6.2 Essential use cases
