GCD Design – Version Dated 2005-08-15
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Author |
Peter Calvert |
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Date |
29 Oct 2005 |
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Version |
1.3 |
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Status |
Final |
Synopsis
This document describes the design of the Global Common Data taxonomy formally dated 2005-08-15 which has been released as a Public Working Draft by XBRL International. The document provides essential explanation for all reviewers and prospective users of the GCD Discoverable Taxonomy Set.
CONTENTS
5. Handling of Addresses and Other Contact Information
7. Next Steps
A. File List
D Intellectual Property Status
1. Summary and Introduction
This document describes the design of the Global Common Data (GCD) taxonomy formally dated 2005-08-15 which has been released as a Public Working by XBRL International. The document provides important explanation of the taxonomy for all prospective users and reviewers.
The GCD Discoverable Taxonomy Set (DTS) has been formally Acknowledged by XBRL International, confirming it complies with the XBRL Specification. It is listed on the Acknowledged Taxonomies page of the XBRL International website which provides links to the URLs where its files are permanently stored. It is available for download as a single zip file from http://www.xbrl.org/int/gcd/2005-08-15/int-gcd-2005-08-15.zip.
To view the full content of the DTS, open the file int-gcd-pres-2005-08-15.xsd in a taxonomy viewer. This will import other schema in the DTS. The zip also contains Excel versions of the taxonomy as well as this explanatory document. Appendix A shows a full list of files in the zip.
We are grateful for all constructive feedback on this important taxonomy as we move it towards final status. Public comment may be sent to domain@xbrl.org. Members of XBRL International may provide direct comment on the International Domain e-Group.
This document assumes familiarity with the main principles of taxonomy design, the Financial Reporting Taxonomies Architecture [FRTA] and the 2.1 Specification [SPEC].
2. Purpose and Status
The GCD is intended to cover common information which may typically be required in business reporting. It provides a standard way to represent this data in XBRL, supporting interoperability and comparison between XBRL implementations around the world. It offers a core set of taxonomies which taxonomy authors may import, saving time and effort in building their taxonomies.
It is intended to meet requirements for both financial and GL reporting.
Earlier draft versions of the GCD have been created under previous versions of the XBRL Specification. This new GCD, based on the 2.1 Specification, benefits from experience from those past efforts and input from an international GCD working group formed to coordinate views on requirements and design.
3. Structure and Main Content
The structure of the international GCD DTS is shown in the figure 1. It consists of a core taxonomy which provides basic elements and structures and a number of extension “data type” taxonomies which define particular sets of data, including elements representing countries and languages. Two ”entry-point” taxonomies, one including a presentation linkbase, one without, complete the DTS.
This approach provides flexibility in defining and maintaining data elements and allows easy and meaningful extension, for example at the jurisdiction or industry level. Elements in the data type taxonomies are matched to underlying elements in the core taxonomy by appropriate use of substitution groups. This is explained in more detail in section 4 on Use of the GCD.
Although the GCD provides an example of the use of substitution groups and extension by data type taxonomies, it is not intended to represent a specification of how they should be used. That is the domain of dedicated XBRL technical guidance documents.
Figure 1.
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The Core GCD (namespace prefix: int-gcd) consists of a schema file and label linkbase. It defines a set of elements, tuple structures and datatypes which provide a foundation for the GCD DTS. They provide a basis for describing:
a. Entity and entity-related information. This includes name, trading and former names, identifying codes, legal form, activities, contact information, public listing information and third party agents.
b. Instance Documents which may be produced from the taxonomy. This includes document name, version, revision history, authors, languages and contact information.
c. Dates and periods covered by the business report being represented in XBRL.
d. General contact information, including elements and structures representing address components, phone numbers and website URLs.
e. Common information such as countries, languages and exchanges.
The Main Data Types taxonomy (namespace prefix: int-gcd-dt) provides a set of elements to extend the basic information represented in the core taxonomy. Among other things, it defines various types of third party agent (banker, accountant, lawyer, underwriter etc.), types of entity contact (investor relations, sales, technical etc), types of website (media relations etc.), types of general contact (day, night, emergency etc), types of address (street, postal) and types of phone number (mobile, landline etc.) It currently contains 35 elements. It consists solely of a schema file and label linkbase.
The Countries Taxonomy (namespace prefix: int-gcd-cntr) provides elements representing countries based on the International Standards Organisation (ISO) countries standard. It consists of schema, label, presentation and reference linkbases. The reference linkbase contains references to the ISO country codes and date of update for versioning purposes. It contains 241 elements.
The Languages Taxonomy (namespace prefix: int-gcd-lang) provides elements representing languages based on the ISO languages standard. It consists of schema, label, presentation and reference linkbases. The reference linkbase contains references to the ISO language codes and date of update for versioning purposes. It contains 103 elements.
The Exchanges Taxonomy (namespace prefix: int-gcd-exch) provides elements representing stock exchanges based on the ISO market identification code (MIC) standard. It consists of schema, label, presentation and reference linkbases. The reference linkbase contains references to the ISO MICs and date of update for versioning purposes. It contains 178 elements.
The Currencies Taxonomy (namespace prefix: int-gcd-curr) provides elements representing currencies based on the ISO currencies standard. It consists of schema, label, presentation and reference linkbases. The reference linkbase contains references to the ISO currency codes and date of update for versioning purposes. It contains 183 elements.
Other Data Type taxonomies may be required in due course at the international GCD level. A possible example is an Entity Activity Data Types taxonomy, which might include elements for SIC, NACE and similar classifications.
Some elements in data type taxonomies will take values when used in instances: an example is a company registration number, whose value will be the registration number itself. However, many elements in data type taxonomies, including countries, languages, exchanges and currencies, effectively represent a value in themselves. They add meaning to an instance by either being present or not present. They do not take a further value. Such elements and their data types are defined in the GCD as having nil content.
The Entry-point Taxonomy (namespace prefix: int-gcd-entr) and the Presentation Taxonomy (namespace prefix: int-gcd-pres) provide convenient single points of entry or reference to the GCD for those wishing to use the GCD DTS. The Entry-point taxonomy simply imports all the GCD components. The Presentation Taxonomy does the same but adds a presentation linkbase so the elements and components can be viewed in a structured and intelligible way.
In practice, prospective users and reviewers will want to use the Presentation Taxonomy to view and understand the GCD, but taxonomy authors may want to import the Entry-point Taxonomy so they are not encumbered by the presentation of the full GCD content. They can then select or organise the presentation of relevant GCD elements via their own presentation linkbase(s).
4. Use of the GCD
We expect National Common Data taxonomies to extend the GCD, adding elements to the substitution groups defined in the GCD. Obvious examples of data types which are defined at a national rather than global level are national entity identifying codes – such as company registration numbers or local tax authority codes. The substitution group of these elements will make their purpose globally recognisable, even if the precise meaning of the element is defined at a national or jurisdiction level.
For example, a “VAT registration number” element in the Dutch extension to the GCD would take the data type “int-gcd:entityIdentifierCodeItemType” and appear in the substitution group “int-gcd:entityIdentifierCodeItemHead”. (If the Dutch extension imported the GCD presentation taxonomy, the element could be presented as a grandchild of Entity Identifying Codes, although it is more likely that a Dutch taxonomy author might create a presentation view of elements suited purely to local purposes.)
Decisions on which elements are included in the international GCD and which are left to be defined at the local level are open to debate. It is likely that more elements will be added in the international data type taxonomies as we gain experience and greater insight into jurisdiction requirements and the use of the GCD. This issue is covered more fully under section 5, Design and Content Issues.
Clearly, users of the GCD may import either the full DTS or individual taxonomies within the DTS. A taxonomy author who simply required the set of country elements could import the Countries Taxonomy.
An important principle of the GCD is that it provides reusable tuples covering key areas of data, notably for contacts and addresses. This helps taxonomy authors using the GCD to create their taxonomies with efficiency, flexibility and consistency.
For example, the Core GCD defines a “General Contact Information” tuple which includes a “Contact Person” and a “Contact Details” tuple. The “Contact Details” tuple in turn contains tuples representing “Address” and “Phone Number”. Any one of these tuples may be reused in taxonomies which import the GCD. Elements which are heads of substitution groups and contained within the appropriate tuple define the type or form of contact information. Standard elements in these substitution groups are defined in the Main Data Types taxonomy. Examples include standard types of contact such as “office”, “home”, “day”, “night”, “emergency”. Taxonomies extending the GCD may add elements in appropriate substitution groups to reflect local requirements. For example, the Ruritania Rich Business Tax Return taxonomy might want to add elements under “form of contact” to cover “holiday villa” and “yacht”. The next section provides some further detail on the use of addresses within the GCD.
In summary, the use of taxonomy modules, generic tuples and substitution groups in the GCD allows clear and consistent definition, easy and efficient reuse of components, and flexible and meaningful extension.
5. Handling of Addresses and Other Contact Information
To handle address, the GCD does not define a specific address format. There is obviously no single format which will satisfy the world at large. Instead it defines a set of 26 basic address elements, ranging from specific concepts such as Postal/Zip Code, PO Box, to generic ones such as Address Line 1. We expect local / jurisdiction extension GCDs to define the precise address tuples which are required for local purposes using the elements defined in the core GCD. (For example, a standard UK tuple as required for normal company financial reporting in the UK would comprise "address line 1; address line 2; address line 3; town/city; county; postal/zip code; country". Clearly, other countries will have different patterns and incorporate different elements in their standard address tuples. A typical Japanese address might be based around: "Prefecture; City; Area name; Sub-area, Block number, Building number, Building name, Floor information".)
Since local GCD extensions will define the content of the address tuple, the core GCD simply includes an Address abstract tuple as a placeholder for local definitions.
Contact information tuples contain elements heading substitution groups which describe the type, form and nature of contact -- as described above -- as well as the basic address, phone and e-mail tuples themselves. The descriptive elements allow distinction between types of address (main, street and postal), form of contact (office, home, day, night, emergency etc), and type of phone contact (landline, mobile, fax, telex).
Further sets of elements define the purpose of the contact information. (These range from Entity Registered Office, Entity Bankers through Media Relations Contact to a host of other purposes.)
The GCD does not use individual elements which combine address with purpose such as "EntityRegisteredOfficeStreetName" or “InvestorRelationsSwitchboardAreaCode” etc etc. This would lead to a totally impractical proliferation of elements.
The country schema included in the GCD DTS provides elements for the country part of address.
6. Design and Content Issues
This section highlights some issues which may be considered during review of the taxonomy. It does not attempt to discuss these points in detail – that may be done during the review process itself.
1. Structure and Modularity.
The chosen structure is intended to achieve a reasonable balance between creating manageable, easily-maintained and reusable components on the one hand and unnecessary and potentially confusing fragmentation on the other. The choice of DTS components, including schema files and linkbases, is intended to support their flexible and efficient use in other taxonomies.
2. National versus International Definition of Data Types Elements.
The principles we are following in determining whether elements are defined at the international or jurisdictional or national level are:
1 The international GCD should be limited to essential data items which (a) have broad international use and (b) can be clearly and unambiguously defined at an international level. We are not including items which may be superficially similar but have significantly different meanings at a national level.
2 Local GCD extensions should cover items which are primarily defined and used at a national or local level. For example, many company identification schemes are national rather than international. We do not have the resources at an international level to combine all national schemes and maintain a single list or set of lists of these in an international GCD. Instead, local taxonomy or instance creators who need to make use of a scheme from another jurisdiction should simply import or refer to that jurisdiction’s Data Types taxonomy.
We should define the conventions for the naming of national or local GCD taxonomy files and perhaps other processes to ensure these files are easy for international users to locate.
We will also monitor local GCD content and requirements in order to identify data sets which should be included in later versions of the international GCD. Potential candidates for inclusion at international level include some elements describing Entity Activity, Operational Status and Entity Officers.
3. Cardinality.
The cardinality of items in tuples in the Core GCD has been carefully set to enable flexible re-use. The choice of correct cardinality in all cases is not obvious. In considering cardinality, reviewers should consider all potential uses of a tuple.
4. Signatures.
The draft GCD does not include a signature tuple or other constructs which might support assurance information. It has been proposed that the GCD might usefully represent information on e-signatures, how instances relates to traditional published information and what sections have auditors’ approval. Requirements and means of modelling such assurance data have not yet been sufficiently discussed to determine what a GCD should contain in this area.
5. Patterns in String Items.
We may need to add further patterns to some string items in the core GCD to add in validation. One example is the e-mail address element, which could be constrained to include …@..... These requirements are still TBD.
6. Names.
The current GCD uses a single string element for people's names. This is for two reasons: (a) it appears to meet the immediate priority requirements and (b) going beyond a single field adds significant complexity. We will review the approach to this in the light of discussions on the use of various Name standards, including the new OASIS draft standard.
7. Instance Naming and Identification Convention.
We require a convention for establishing unique filenames (or other identifiers) for instances. The core GCD defines a “unique filename” element, but we have no proposed convention for populating this.
8. Maintenance of the GCD and its Datatype Taxonomies.
XBRL International will need to put processes in place to maintain the GCD and its Datatype Taxonomies, such as those for Countries, Languages and Exchanges. The latter are based on ISO standards and are unlikely to change frequently, but amendments and updates will be required from time-to-time.
7. Next Steps
Next steps are to gather feedback on the Public Working Draft of the GCD and to gain insight into its strengths and weaknesses by using it or its components within jurisdiction and other taxonomies. The Netherlands and UK have both stated an intention to incorporate the new GCD in their new jurisdiction taxonomies (the Dutch taxonomy framework and UK GAAP taxonomy). Feedback from its use in conjunction with the XBRL GL taxonomy will also be particularly helpful.
We expect to continue to improve the GCD, producing new Public Working Drafts in the light of feedback, as we move towards a final version. The latter will go through higher stages of the XBRL recognition process, which currently involve Approval for taxonomies and Recommendation for XBRL publications. These stages will reflect its satisfactory use in real XBRL implementations.
APPENDICES
A. File List
The following is a list of files contained in the draft GCD DTS zip, int-gcd-2005-08-15.zip:
Core Taxonomy
int-gcd-2005-08-15.htm
int-gcd-2005-08-15.xsd
int-gcd-2005-08-15-label.xml
Main Data Types Taxonomy
int-gcd-dt-2005-08-15.htm
int-gcd-dt-2005-08-15.xsd
int-gcd-dt-2005-08-15-label.xml
Countries Taxonomy
int-gcd-cntr-2005-08-15.htm
int-gcd-cntr-2005-08-15.xsd
int-gcd-cntr-2005-08-15-label.xml
int-gcd-cntr-2005-08-15-presentation.xml
int-gcd-cntr-2005-08-15-reference.xml
Currencies Taxonomy
int-gcd-curr-2005-08-15.htm
int-gcd-curr-2005-08-15.xsd
int-gcd-curr-2005-08-15-label.xml
int-gcd-curr-2005-08-15-presentation.xml
int-gcd-curr-2005-08-15-reference.xml
Exchanges Taxonomy
int-gcd-exch-2005-08-15.htm
int-gcd-exch-2005-08-15.xsd
int-gcd-exch-2005-08-15-label.xml
int-gcd-exch-2005-08-15-presentation.xml
int-gcd-exch-2005-08-15-reference.xml
Languages Taxonomy
int-gcd-lang-2005-08-15.htm
int-gcd-lang-2005-08-15.xsd
int-gcd-lang-2005-08-15-label.xml
int-gcd-lang-2005-08-15-presentation.xml
int-gcd-lang-2005-08-15-reference.xml
Presentation Taxonomy: entry taxonomy with presentation linkbase
int-gcd-pres-2005-08-15.htm
int-gcd-pres-2005-08-15.xsd
int-gcd-pres-2005-08-15-presentation.xml
Entry Taxonomy: no presentation linkbase
int-gcd-entr-2005-08-15.htm
int-gcd-entr-2005-08-15.xsd
References Taxonomy: provides reference part definitions
int-gcd-ref-2005-08-15.xsd
Excel Exports of Taxonomy
int-gcd-2005-08-15-Tree.xls
int-gcd-2005-08-15-Elements.xls
Design Document (this note)
gcd-design-2005-08-15.htm
gcd-design-2005-08-15.rtf
B. Acknowledgements
An international working group, formed under the auspices of XBRL in Europe (XiE) and the International Domain Working Group, coordinated views on requirements and design of the new GCD. It comprised Jose Ramon Cano, Camille Dumm, Norbert Flickinger, Yuji Furusho, Marc van Hilvoorde, Brad Homer, Josef Macdonald, Marko Roos, Paul Warren and Peter Calvert. Many others outside the working group, notably Walter Hamscher, Ignacio Hernandez-Ros, Eric Cohen, David vun Kannon and George Farkas and the IASCF XBRL Team, provided valuable comment and suggestions. The new draft GCD also draws on previous versions GCD and contributions to taxonomy design by many members on the International Specification and Domain Working Groups.
The support of XBRL in Europe (XiE) during both the design and the development stage of the taxonomy was crucial to its completion.
C References
[FRTA] Financial Reporting Taxonomies Architecture, Version 1.0, Recommendation dated 2005-04-25.
[SPEC] XBRL International Specification, Version 2.1, dated 31 December 2003, with Corrected Errata dated 29 April 2004.
D Intellectual Property Status
© XBRL International 2005, © XBRL in Europe 2005, All rights reserved.
This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to XBRL International or XBRL organisations, except as required to translate it into languages other than English. Members of XBRL International agree to grant certain licenses under the XBRL International Intellectual Property Policy (http://www.xbrl.org/legal).
This document and the information contained herein is provided on an "AS IS" basis and XBRL INTERNATIONAL DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
The attention of users of this document is directed to the possibility that compliance with or adoption of XBRL International specifications may require use of an invention covered by patent rights. XBRL International shall not be responsible for identifying patents for which a license may be required by any XBRL International specification, or for conducting legal inquiries into the legal validity or scope of those patents that are brought to its attention. XBRL International specifications are prospective and advisory only. Prospective users are responsible for protecting themselves against liability for infringement of patents. XBRL International takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Members of XBRL International agree to grant certain licenses under the XBRL International Intellectual Property Policy (http://www.xbrl.org/legal).
E Document History
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Date |
Author |
Summary of changes |
|
15 Jan 2005 |
Calvert |
First draft based on discussions of GCD Working Group at a meeting in Amsterdam and subsequent e-mail exchanges. |
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10 Feb 2005 |
Calvert |
Significant revisions based on feedback from GCD Working Group. Expansion of section 2.3 on enumerated list issue. Addition of Entity Context and Issues sections. Editing changes in other sections. Number of detailed changes to the contents definition in Appendix A. |
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6 Oct 2005 |
Calvert |
Complete rewrite of document as it becomes a description of a completed draft taxonomy rather than the outline of a design. New sections describe the structure and main content of the taxonomy, the handling of address and remaining issues. The rewrite reflects the resolution of issues highlighted in previous versions and decisions on the detailed design of the taxonomy taken during its construction. |
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29 Oct 2005 |
Calvert |
Added description of currencies taxonomy; added paragraph on nil content. Other changes to reflect change of status to public working draft, including addition of IP statement. Updated file list and Acknowledgements. Some other detailed editing changes based on feedback to create final version of document describing 2005-08-15 taxonomy. |
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