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This glossary contains short definitions of terms related to IFRS Taxonomy as well as explanations of major XBRL concepts.



abstract attribute

an abstract attribute appears on items definitions in schemas; its possible values are "true" and "false"; "true" indicates that the item must not appear in instance documents; abstract elements (elements for which abstract attribute is "true") are intended to support the presentation of business reports in XBRL;

more: XBRL Spec: Terminology; Example 51;


according to XBRL Specification 2.1 arcs relate concepts to each other by associating their locators; they also link concepts with resources by connecting the concept locators to the resources themselves; arcs are also used to connect fact locators to footnote resources in footnote extended links; arcs have a set of attributes that document the nature of the expressed relationships ; in particular they possess attributes: type (whose value must be "arc"), from, to and arcrole;


  xlink:from="AssetsTotal" xlink:to="AssetsCurrent"
  weight="1.0" order="1"/>

more: XBRL Spec: Terminology;;

arcrole attribute

an arcrole is an XLink attribute that describes the meaning of resources within the context of a link; it may be used on arc- and simple- type elements; on arcs it determines the semantics of the relationship that is being described or, in other words, it documents the kind of relationship that the arc expresses; there is a set of standard arcroles defined for specific arcs (labelArc, referenceArc, calculationArc; definitionArc, presentationArc and footnoteArc); the value of arcrole must be an absolute URI, (e.g. in presentation linkbase on presentationArc it is "http://www.xbrl.org/2003/arcrole/parent-child");

more: XBRL Spec:;;


according to the XML Specification 1.1, attributes are used to associate name-value pairs with elements; attribute specifications must not appear outside of start-tags (<...>) and empty-element tags (<.../>); each attribute specification has a name and a value; XML attribute types are of three kinds: a string type (any literal string as a value), a set of tokenized types (varying lexical and semantic constraints), and enumerated types;

more: XML Spec: 3.3;


balance attribute

a balance is an optional attribute that appears on items which type is monetaryItemType; it is tokenized and may be assigned values "credit" or "debit"; according to the basic rule of double entry accounting, assets and expenses have a normal debit balance while equity, liabilities and revenues have a normal credit balance; other monetary elements may be assigned a balance attribute to improve calculation validation by restricting the sign of the value;

more: XBRL Spec:; FRTA 2.2.3; 2.2.4;

base taxonomy

a base taxonomy is a taxonomy that is used as the foundation for the creation of an extension;

more: XBRL Spec:; FRTA 2.2.3; 2.2.4;


calculation linkbase

a calculation linkbase is a linkbase that contains mathematical relationships such as addition and subtraction (see weight attribute) between numeric items defined in a schema document;

more: XBRL Spec: 5.2.5 ; FRTA 3.3;

calculationArc element

a calculationArc is an XLink arc element; it defines how concepts relate to each other for calculation purposes; one standard arcrole value defined for this element is "http://www.xbrl.org/2003/arcrole/summation-item";


  xlink:from="AssetsTotal" xlink:to="AssetsCurrent"
  weight="1.0" order="1"/>

more: XBRL Spec: 5.2.5; FRTA 3.3;


concepts are defined in two equivalent ways:

  1. in a syntactic sense, a concept is an XML Schema element definition, defining the element to be in the item element substitution group or in the tuple element substitution group;
  2. at a semantic level, a concept is a definition of a kind of fact that can be reported about the activities or nature of a business activity;

source: XBRL Spec: Terminology;

concept-label relation

a concept-label relation concerns arcrole value on a labelArc element which is "http://www.xbrl.org/2003/arcrole/concept-label"; it is used from a concept locator (loc element) to a label element and it indicates that the label conveys human-readable information about the concept;

more: XBRL Spec:;

concept-reference relation

a concept-reference relation concerns arcrole value on referenceArc element which is "http://www.xbrl.org/2003/arcrole/concept-label"; it is used from a concept locator (loc element) to a resource element and it indicates that the reference is to materials documenting the meaning of the concept;

more: XBRL Spec:;

context (inc. context element)

context is defined as:

  1. background of the value of the business concept; component of the business fact;
  2. an element that occurs as a child of the xbrl element in XBRL instances; it documents the entity, the period and the scenario that collectively give the appropriate context for understanding the values of items;


<xbrli:context id="Current_AsOf">
    <xbrli:identifier scheme="www.example.com">Sample Company</xbrli:identifier>

more: XBRL Spec: 4.7;

cross-context rule

the cross-context rule concerns instance documents and calculation linkbase and relates to impossibility to perform calculations between numeric items appearing in different contexts (i.e. when one is a flow and in its definition periodType value is set to 'duration' and the other is a resource and it is described as instant); typically, flows appear in Income statements and Statements of cash flows while resources are listed on Balance sheets; mix contexts (flows and resources together) occur whenever movements from a resource state at one point in time to another are to be calculated in a report or any kind of explanatory disclosure (for example, in the Statement of changes in equity, Changes in assets, etc.); thecross-context problem may be overcome using a formula linkbase and the functions that it provides;


decimals attribute

the decimals attribute appears on numeric items (facts) in instance documents; it specifies the number of decimal places to which the value of the fact represented may be considered accurate, possibly as a result of rounding or truncations; it must be an integer or possess the value "INF" meaning that the number expressed is the exact value of the fact; the decimals attribute must not occur together with the precision attribute on the same fact element;

more: XBRL Spec: 4.6.5;

definition linkbase

a definition linkbase is a linkbase that is intended to contain a wide variety of miscellaneous relationships between concepts in taxonomies; four standard relations expressed by this linkbase are "general-special", "essence-alias", "similar-tuples" and "requires-element";

more: XBRL Spec: 5.2.6; FRTA 3.4;

definitionArc element

a definitionArc is an XLink arc element; it defines different types of relationships that may appear between concepts; there are four standard arcrole values defined for this element and they are:


<definitionArc xlink:type="arc" xlink:from="postalCode" xlink:to="zipCode" xlink:arcrole="http://www.xbrl.org/2003/arcrole/general-special" order="1"/>

more: XBRL Spec: 5.2.6;


the term dimensions in XBRL relates to the ability to express multidimensional financial information; for example profit from sales could be presented by products, regions, segments, etc; to express such relations, XBRL International developed the Dimension 1.0 Specification that enriches the general XBRL Specifications with rules and procedures on how to construct dimensional taxonomies and instance documents; this specification has been a Candidate Recommendation since December 31, 2005;

more: XBRL Dimensions 1.0 Candidate Recommendation dated 2005-12-31;


a DTS is a collection of taxonomy schema documents and linkbases; the bounds of a DTS are such that the DTS includes all taxonomy schemas and linkbases that can be discovered by following links or references in the taxonomy schemas and linkbases included in the DTS; at least one taxonomy schema in a DTS must import the xbrl-instance-2003-12-31.xsd schema;

source: XBRL Spec: Terminology;



according to the XML Specification 1.1, each XML document contains one or more elements, the boundaries of which are either delimited by start-tags (<…>) and end-tags(</…>), or, for empty elements, by an empty-element tag (<…/>); each element has a type, is identified by name and may have a set of attribute specifications; in XBRL, elements are defined and assigned attributes in schemas and may appear either as items or as tuples; instance documents contain elements together with they content and information about the context that they are associated with;


  id="ifrs_AssetsTotal" name="AssetsTotal"
  type="xbrli:monetaryItemType" substitutionGroup="xbrli:item"
  xbrli:periodType="instant" xbrli:balance="debit" nillable="true" />

more: XML Schema: 3.3.2;

element's content (value)

an element’s content appears between a start-tag (<...>) and a closing-tag (<.../>); in the example <Asset>1000</Asset> the number ‘1000’ is the content; content depends on the type of an element; empty elements (<.../>) have no content but they may carry information in their attributes or simply appear in instance documents;

entity element

an entity is a required element in a context; it identifies the entity that is reporting the facts; it must contain an identifier element and may include a segment description;


  <identifier scheme="http://www.nasdaq.com">COMPANY</identifier>

source: XBRL Spec: 4.7.3;

essence-alias relation

an essence-alias relation concerns arcrole value on a definitioneArc element which is "http://www.xbrl.org/2003/arcrole/essence-alias"; it connects items that have similar meaning in terms of business reporting and must be consistent as described in XBRL Spec.;

extended link element

an extended link is a link that associates an arbitrary number of resources; the participating resources may be any combination of remote an local; in other words, extended links represent a set of relationships between information that they contain and information contained in third party documents; as a part of a taxonomy, extended links are grouped in linkbases and provide additional information about concepts by expressing relations they come into; in particular, extended links contain locators, resources (e.g. label, reference,...) and arcs;

more: XBRL Spec: 3.5.3;



a fact is a concept placed in a context and has an assigned value; facts appear in instance documents; they can be simple, in which case their values must be expressed as simple content (except in the case of simple facts whose values are expressed as a ratio), and facts can be compound, in which case their value is made up from other simple and/or compound facts; on the schema level, simple facts are expressed using items and compound facts are expressed using tuples; the comparison between a concept and a fact is presented in the table below:



Intangible Assets

Intangible Assets as of December 31, 2003 amounted to 300,000 GBP

more: XBRL Spec: 4; FRTA 2.2.2;


footnotes appear in instance documents and provide additional information about facts; for example, several facts may be linked to the sentence: "Including the effect of merger with Sample Company"; to express these connections; XBRL utilizes footnoteLink extended link element; as a kind of linkbases, footnoteLinks enclose locators to the instance documents’ facts; footnotes use footnoteArcs with arcrole value set to "http://www.xbrl.org/2003/arcrole/fact-footnote" to connect facts to additional information;

<Assets id="AssetsID" decimals="0" contextRef="Current_AsOf"
<link:loc xlink:type="locator" xlink:href="#AssetsID"
<link:footnoteArc xlink:type="arc"
  xlink:from="AssetsLocator" xlink:to="AssetsFootnote" order="1.0"/>
<link:footnote xlink:type="resource" xlink:label="AssetsFootnote"
  xlink:role="http://www.xbrl.org/2003/role/footnote" xml:lang="en">
  For more information see Disclosures on Asset</link:footnote>

more: XBRL Spec: 4.11;

footnoteArc element

a footnoteArc is an XLink arc element; it appears in instance documents in footnoteLink extended link and connects facts with additional human-readable information (footnote) relating to them; one standard arcrole value defined for this element is "http://www.xbrl.org/2003/arcrole/fact-footnote".


  xlink:to="iascf-fs_ContributionsNote" order="1.0"/>

more: XBRL Spec:;

footnoteLink element

a footnoteLink element is an extended link appearing in instance documents; it contains locators, resources and arcs which describe additional information for facts by providing footnotes;

more: XBRL Spec: 4.11.1;

formula linkbase

a formula linkbase is a new linkbase that is being developed by XBRL International; it aims to satisfy the formula linkbase requirements document by providing a generalized mechanism to build formulae based on XBRL concepts and XBRL dimensions; formulae can be used to describe business rules for creating new XBRL facts in new instance documents and for describing consistency checking for instance documents; the formula linkbase specification is at the stage of Internal Working Draft;

more: XBRL Formula Requirements Candidate Recommendation dated 2005-06-21;

from attribute

from is a XLink attribute and appears on arcs; its value must be equal to the value of a label attribute of at least one locator or resource on the same extended link as the arc element itself; its value must be an XML NCName (i.e. it must begin with a letter or an underscore);

more: XBRL Spec:;


FRTA stands for Financial Reporting Taxonomy Architecture; it is a document published by the XBRL International Consortium that recommends architectural rules and establishes conventions that assist in comprehension, usage and performance among different financial reporting taxonomies; it is aimed to be applied mainly by public taxonomy developers (authorities); its latest version is a recommendation from April 25, 2005;

source: FRTA Abstract;


the term functions in XBRL relates to XPath 2.0 functions adapted to aid in the querying and creation of XBRL instance documents; XBRL Functions 1.0 is at the stage of Internal Working Draft;

more: XBRL Functions Requirements 1.0 Candidate Recommendation of 2005-06-21;


general-special relation

a general-special relation concerns arcrole value on a definitionArc element which is "http://www.xbrl.org/2003/arcrole/general-special"; it is used to express relationships between concepts when one has more generic meaning than the other; the most common example is Postal Code for which the specific case is Zip Code used in the United States;

more: XBRL Spec:;


href attribute

href is an attribute that supplies the data that allows the XLink application to find a remote resource (or its fragment); it must be used on locators; its value must be a URI;

more: XLink Spec: 5.4;


id attribute

an id attribute may appear on elements and attributes; its value must fulfil the same requirements as those imposed on the name attribute; it uniquely identifies elements or attributes which bear them; locators point to elements using the elements' ids; the id attribute must appear on context and unit elements;

more: XBRL Spec:;; 4.1.1; 4.7.1;;

identifier element

an identifier is an element that appears on the entity element; it specifies the scheme for identifying business entities using a required scheme attribute that contains the namespace URI of the identification system; it provides a framework for referencing naming authorities;



<identifier scheme="http://www.nasdaq.com">SAMP</identifier>

The company with NASDAQ ticker symbol SAMP.

source: XBRL Spec:;

IFRS Taxonomy

the IFRS Taxonomy is a taxonomy developed by the IFRS (International Accounting Standards Committee) Foundation that represents concepts defined in IFRSs and relations between them; its latest version dated May 15, 2005 is Acknowledged under the XBRL International Taxonomy Recognition Process; it contains three schemas, 40 relationship linkbases; reference linkbase and labels in English, German, Portuguese and Japanese; more details can be found on its summary page;

import element

an import element is used to add many schemas with different target namespaces to a schema document; it contains a required attribute namespace and optional id and schemaLocation; at least one taxonomy schema in a DTS must import the xbrl-instance-2003-12-31.xsd schema;


  schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />

more: XBRL Spec: 5.1; XML Schema Structures 4.2.3;

include element

an include element is used to add multiple schemas with the same target namespaces to a schema document; it contains a required attribute schemaLocation and optional id;


<include schemaLocation="../../bus/gl-bus-2005-07-12.xsd"/>

more: XML Schema Structures 4.2.1;


IFRSs (International Financial Reporting Standards) together with International Accounting Standards (IAS) constitute a set of accounting rules issued by the International Accounting Standards Board; they are regarded as a ‘principle-based’ set of standards and are used across the world;

instance document

an instance document is a business report in the XBRL format; it contains tagged business facts (whose definitions can be found in the schemas that the instance document refers to), together with the context in which they appear and unit description; the root element of XBRL instances is <xbrl>;

more: XBRL Spec: 4;


an item is referred to in two ways:

  1. "item" is a value of the substitutionGroup attribute on an element in a schema;
  2. an item is an element in the substitution group for the XBRL item element; in an instance document an item contains the value of the simple fact and a reference to the context (and unit for numeric items) needed to correctly interpret that fact; when items occur as children of a tuple, they must also be interpreted in light of the other items and tuples that are children of the same tuple; there are numeric items and non-numeric items, numeric items require to document their measurement accuracy (precision and decimals) and units of measurement;

more: XBRL Spec: 4.6; FRTA 2.2;


ITMM stands for IFRS Taxonomy Modules Manager; it was developed by the IFRS Foundation XBRL Team to help users manage the modularized IFRS taxonomy; it generates a ‘shell’ schema or an instance document that imports presentation and calculation linkbases as specified by the user;




label element

label elements appear in label linkbases on labelLink extended links; they provide human readable information about concepts they are connected to (using arcs and locators); this information may be carried by a label element which may vary from a simple label to a wide documentation of the concept; the content of the label element can be mixed and it may contain any string and/or a fragment of XHTML; it must contain the xml:lang attribute that describes the language of the content; an optional role attribute may provide additional information about the type of a label (details in XBRL Spec Table 8) indicating whether the label is a standard one (no role or role set to "http://www.xbrl.org/2003/role/label") , a documentation one ("http://www.xbrl.org/2003/role/documentation"), a measurement guidance one ("http://www.xbrl.org/2003/role/measurementGuidance"), etc.;

more: XBRL Spec: ;

labelArc element

a labelArc is an XLink arc element; it connects concepts with label resources; one standard arcrole value for this element is "http://www.xbrl.org/2003/arcrole/concept-label";


<labelArc xlink:type="arc"
  xlink:from="AssetsTotalLocator" xlink:to="AssetsTotal_LabelLocator" />

more: XBRL Spec:;

label linkbase

a label linkbase is a linkbase that contains relations between concepts defined in a schema and human-readable resources such as labels and documentation in different languages;

more: XBRL Spec: 5.2.2;

label attribute on locators

a label attribute on locators identifies the locator so that arcs in the same extended link can reference it; xlink:label attribute value is an NCName (this requirement means that it must begin with a letter or an underscore);

more: XBRL Spec:;

lang attribute

lang is an XML attribute that is used to identify the language in which the element's content is written; the values of this attribute must be language identifiers as defined by IETF RFC 3066;

more: XML Recommendation: 2.12;


a linkbase is a collection of XLink extended links that document the semantics of concepts in a taxonomy; linkbases (often referred to as 'layers') fall in one of the three categories:

  1. relation linkbases (calculation, definition and presentation) that manage the relations between taxonomy elements;
  2. label linkbases that associate taxonomy elements with text written in various languages;
  3. reference linkbases that connect concepts with authoritative literature;

The root element of all linkbases is <linkbase>

more: XBRL Spec: 5.2;

linkbase element

a linkbase element is the root element of linkbases and is intended to be used as a linkbase container, holding namespace prefix definitions and the schemaLocation attribute; it may enclose one or more extended links;

more: XBRL Spec: 5.2.1; 3.5.2;

loc element

a loc element appears on extended links and is used to locate elements defined in a schema (is acts as a locator); locators require attributes xlink:href and xlink:label;


  xlink:label="ifrs_AssetsTotalLocator" />

more: XBRL Spec:;


locators supply an XPointer reference to the taxonomy schema element definitions that uniquely identify each concept; they provide an anchor for extended link arcs; for consistency there is only one locator defined for use in all XBRL extended links and it is <loc> element;

more: XBRL Spec:;


maxOccurs attribute

a maxOccurs attribute appears in XBRL mainly on element references in tuples; it indicates the maximum number of an element's occurrences on the tuple; its value must be a positive integer and the default is "1"; to express an unknown or infinite number the expression "unbounded" is used;


<element ref="ifrs:NatureOfClassOfProvision" minOccurs="0" maxOccurs="3"/>

more: XML Schema : Occurrence Constraints;


metadata is data about data (literally, since it is composed of Greek word meta and Latin term data, both meaning ‘information'); in XBRL it could be explained as a computer understandable information about business concepts; the accounting term Asset is very meaningful to a persons familiar with financial reporting, but has no meaning to a computer until it is told how to interpret it; these definitions appear in schemas and are enriched by linkbases (which inform computers about the relationships between elements and between the elements and other resources); together schemas and linkbases constitute taxonomies;

minOccurs attribute

the minOccurs attribute appears in XBRL mainly on element references in tuples; it indicates the minimum number of an element's occurrences on the tuple; its value must be a positive integer and the default is "1";


<element ref="ifrs:NatureOfClassOfProvision" minOccurs="0" maxOccurs="3"/>

more: XML Schema : Occurrence Constraints;


name attribute

a name attribute appears on the definitions of elements and attributes and assigns them with a unique name; it begins with a letter (or one of the punctuation characters from a specific set) and continues with letters, digits, hyphens, underscores, colons, or full stops which together are known as name characters; they must not begin with he string 'xml' (upper or lower case in any combination), since it is reserved for the XML standardization and specification;


an XML namespace is a collection of names, identified by a URI reference, which are used in XML documents as element types and attribute names; XML namespaces differ from the “namespaces” conventionally used in computing disciplines in that the XML version has an internal structure and is not, mathematically speaking, a set;the XML namespace attribute (xmlns) is placed in the start tag of an element (typically the root element e.g. <schema> or <linkbase>) and possesses the following syntax - xmlns:prefix="namespaceURI";



non-numeric item

a non-numeric item is an item that is not a numeric item, e.g. dates;

source: XBRL Spec: Terminology; more: XBRL Spec:;

numeric item

a numeric item is an item whose content is derived by restriction of XML Schema types decimal, float or double, or has complex content derived by the restriction of the XBRL defined type fractionItemType; reported in an instance document it needs the reference to a unit;

source: XBRL Spec: Terminology; more: XBRL Spec:;



parent-child relation

a parent-child relation concerns an arcrole value on the presentationArc element which is "http://www.xbrl.org/2003/arcrole/parent-child"; it is used to express hierarchical relations between concepts that appear in paper form business reports and stem from financial and accounting principles, rules and regulations;

more: XBRL Spec:;

period element

in XBRL, the term period relates to instant or duration time; in business reporting, financial facts are reported either "as of" a particular date (for example in Balance Sheet) or "for period" (i.e. for the time between two specified dates of which one begins the period and the other ends it); the period element constrains the instant or interval time for reference by an item element in instance documents; different periods are carried by different contexts; to reflect the business reporting idea of instant and duration, the period element may carry either a single instant element or a sequence of startDate and endDate elements or an element forever; the first three elements' content must be a date TimeType (yyyy-mm-dd:Thh:mm:ss) or dateType (yyyy-mm-dd) while the last one is empty;




more: XBRL Spec: 4.7.2;

periodType attribute

a periodType attribute appears on element elements in schemas; it must be used on items; it may be assigned one of the two values "instant" and "duration"; the first one indicates that the element, when used in an XBRL instance, must always be associated with a context in which the period is instant (that is, at the point of time); the later means that this period in instance documents must be expressed either using a sequence of startDate and endDate elements or an element forever;

more: XBRL Spec:;

precision attribute

a precision attribute appears on numeric items (facts) in instance documents; it conveys the arithmetic precision of a measurement and, therefore, the utility of that measurement to further calculations; it must be an integer or possess the value "INF" meaning that the number expressed is the exact value of the fact; the precision attribute must not occur together with the decimals attribute on the same fact element;

more: XBRL Spec: 4.6.4;


when declaring namespaces, they may be associated with prefixes which are used to qualify references to any schema components belonging to that namespace; prefixes, that precede names of elements, attributes and some of their predefined values, provide an indication of where to find definitions of these properties;

presentation linkbase

a presentation linkbase is a linkbase that contains hierarchical presentation relationships between concepts defined in the schemas it refers to; it includes extended links that contain locators of elements and arcs reflecting parent-child relations between them;

more: XBRL Spec: 5.2.4;

presentationArc element

the presentationArc is an XLink arc element; it is used in presentation linkbases to define hierarchical relations between concepts in terms of their appearance in business reports; one standard arcrole value defined for this element is "http://www.xbrl.org/2003/arcrole/parent-child".


  order="1" use="optional"/>

more: XBRL Spec:;



reference element

a reference element appears on referenceLink extended links; it is intended to enable taxonomies to ground the definitions of concepts in authoritative statements in published business, financial and accounting literature; it should provide the information necessary to find the reference materials that are relevant to understanding appropriate usage of the concept being defined, but does not include the reference materials themselves; the reference element carries an arcrole attribute that describes the type of reference being defined (presentation, measurement, definition, etc...); it also contains a set of elements called parts (from their substitutionGroup which is "link:part"); because the structure of reference materials may differ, taxonomy creators are allowed to define their own parts; however, there is a predefined universal set of parts available (http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd and http://www.xbrl.org/2004/ref-2004-08-10.xsd);


<reference xlink:type="resource"
<reference xlink:type="resource"

more: XBRL Spec:;

reference linkbase

a reference linkbase is intended to contain relationships between concepts and references to authoritative statements in the published business, financial and accounting literature that give meaning to the concepts; it includes extended links referenceLink that contain locators of elements defined in schema, reference elements describing resources and arcs presenting concept-reference relations between them;

more: XBRL Spec: 5.2.3;

referenceArc element

a referenceArc is an XLink arc element; it connects concepts with reference resources; one standard arcrole value for this element is "http://www.xbrl.org/2003/arcrole/concept-reference";


  xlink:from="AssetsTotalLocator" xlink:to="AssetsTotal_LabelLocator" />

more: XBRL Spec:;

requires-element relation

a requires-element relation concerns arcrole value on a definitionArc element which is "http://www.xbrl.org/2003/arcrole/requires-element"; it is used to indicate elements required in business reports i.e. concepts that must appear in instance documents;

more: XBRL Spec:;

role attribute

a role is an XLink attribute that describes the meaning of resources within the context of a link; it may be used on extended- and simple- type elements as well as locators and resources; the value of role must be an absolute URI;

root element

a root element is the top level element fulfilling the role of a container for a larger whole; in XBRL such elements could be schema, xbrl and linkbase;


schema document

a schema document contains definitions of concepts; together with linkbases which refer to it, it constitutes a taxonomy; a schema document should specify a target namespace; its root element is schema;

more: XBRL Spec: 5.1;

schema element

a schema element is the root element of schema document; it opens and closes every taxonomy schema; it specifies the target namespace and may assign prefixes to other namespaces used;



  <!-- content - definitions -->


more: XML Schema: 3.15.2;

schemaLocation attribute

a schemaLocation attribute is used in four circumstances:

  • on an xbrl element in instance documents to provide indicators to the application regarding the location of schema documents against which the instance was created;
  • on a linkbase element in linkbases to indicate the application the location of schema documents;
  • (optional) on an import element in schema documents to provide hints to the application regarding the location of schema documents that the author warrants; there it supplies the required components for the namespace identified by the namespace attribute;
  • (required) on an include element in schema documents it contains a URI reference which must identify a schema document; the effect is to compose a final effective schema by merging the declarations and definitions of the including and included schemas;



source and more: XML Schema Primer: 5.6; XML Schema Structures: 2.6.3; XBRL Spec: 4.1;

schemaRef element

a schemaRef element must appear in every instance document as a child of an xbrl element before other parts of an instance; it specifies the taxonomy schemas an instance belongs to.

more: XBRL Spec: 4.2;

segment element

a segment element appears on an entity element in a context definition; it is an optional container for additional tags defined by the instance preparer; it is intended to identify the business segment more completely in cases where the entity identifier is insufficient; in general, the content of a segment will be specific to the purpose of the XBRL instance; this element must not appear empty;



source and more: XBRL Spec:;

scenario element

a scenario is an optional element that appears in instance documents; it allows for additional information to be included in instances; the preparer of an instance defines the tags used to describe the information; this information shall enclose in particular the type of data reported (for example actual, budgeted, restated, pro forma, …)

more: XBRL Spec: 4.7.4;

'shell' schema

a 'shell' schema is produced by the ITMM tool; it refers to the IFRS Taxonomy by importing its schema and user-selected linkbases;

similar-tuples relation

a similar-tuples relation concerns arcrole value on definitionArc element which is "http://www.xbrl.org/2003/arcrole/similar-tuples"; it represents relationships between tuple concepts that have equivalent definitions; for example, this kind of relationship would be appropriate to use between two different tuple concepts that are both designed to describe mailing addresses;

more: XBRL Spec:

substitutionGroup attribute

a substitutionGroup attribute appears on elements' definitions in schemas; XBRL defines two basic substitution groups: items and tuples; its purpose is to indicate which type you can substitute with the actual definition;

summation-item relation

a summation-item relation concerns arcrole value on a calculationArc element which is "http://www.xbrl.org/2003/arcrole/summation-item"; it represents relationships only between concepts that are in the item substitutionGroup and whose type is numeric (e.g. monetary or decimal); the weight attribute defines the algebraic sign of the operation;

more: XBRL Spec:;



mark-up languages such as XBRL use tags to describe data; for example <Asset>1000</Asset> - the word Asset together with the brackets "<" and ">" is called a tag; there are opening tags: <…> and closing tags: </…>.


taxonomy in general means a catalogue or a set of rules for classification; in XBRL, a taxonomy is a dictionary, containing computer-readable definitions of business reporting terms as well relationships between them and links connecting them to human-readable resources (metadata); a typical taxonomy consists of a schema (or schemas) and linkbases; a set of taxonomies that can be discovered from one entry point schema is called DTS;

more: XBRL Spec: 5;

taxonomy extension

taxonomy extensions add concepts and modify the relationships among the concepts in the base taxonomies that they extend; they are created to support specialised reporting requirements in specific accounting jurisdictions, in specific industries, or for specific companies; taxonomy extensions consist of a set of taxonomy schemas and/or linkbases that augment a DTS that includes the base taxonomies.

source: FRTA 5;

to attribute

to is a XLink attribute and appears on arcs; its value must be equal to the value of a label attribute of at least one locator or resource on the same extended link as the arc element itself; its value must be an XML NCName (i.e. it must begin with a letter or an underscore);

more: XBRL Spec:;


a "tuple" is one of two standard values of the substitutionGroup attribute on element element in an XBRL schema; elements possessing this value are often referred to as tuples; according to the XBRL Specification, tuples associate facts that cannot be independently understood and their meaning depends on their relationship to other elements; an example of such a set of facts is a payroll row which consists of the name of the employee, his/her position and salary; each of these elements does not have full meaning without being associated with the others; tuples are commonly used to express tables with known headings and an unknown number of rows;tuples do not carry any human-readable content; instead, they contain other elements; in XML, elements that contain other elements are said to have complex types; additionally, tuples do not possess any content other than their various elements so their complexContent restricts anyType only to the elements referred to; a tuple definition may also contain information on the number of minimum and maximum occurrences of elements possessed as well as their sequence;

<element name="ifrs_ElementReclassified" substitutionGroup="xbrli:tuple">
       <restriction base="anyType">
           <element ref="ifrs:DescriptionOfElementReclassification"
             minOccurs="0" maxOccurs="1"/>
           <element ref="ifrs:CodeOfElementReclassification"
             minOccurs="0" maxOccurs="1"/>
           <element ref="ifrs:FinancialImpactOfReclassification"
             minOccurs="0" maxOccurs="1"/>
       <attribute name="id" type="ID" use="optional"/>

more: XBRL Spec: 4.9; FRTA 2.3;

type attribute

a type attribute may or must appear on different elements; from an XBRL perspective, the most important type attribute appears on concepts definitions in schema which indicate the data types of the described items; XBRL item types were derived from XML data types; the most common types used in financial reporting taxonomies are stringItemType that may contain any string of characters, monetaryItemType that is used in concepts for which there is a need to specify a currency and decimalItemType which is carried by other numeric items; taxonomy creators may create their own types as necessary to express financial information by extending or restricting the available XBRL or XML predefined types; a type attribute must also appear on XLink simple- and extended- links (in particular on schemaRef and linkbaseRef elements);

more: XBRL Spec:;; 4.2.1; 4.3.1;;


unit element

a unit is an element that appears in instance documents and specifies the units in which numeric items (that refer to its required id attribute using unitRef attribute) have been measured; it may define simple units using a measure element and complex units providing divide element and its subelements (unitNumerator and unitDenominator); there are several constraints imposed on this element, its children and their content; for example monetary concepts must refer to ISO 4217 currency codes;



<unit id="U-GBP">
  <measure xmlns:ISO4217="http://www.xbrl.org/2003/iso4217"> ISO4217:GBP</measure>

Currency, UK Pounds

<unit id="percent">

Pure number (%, number of employees)

<unit id="u1">

Number of shares

<unit id="u6">

EPS (Earnings Per Share) in Euros per share

more: XBRL Spec: 4.8;

URI reference

URI stands for Uniform Resource Identifier and is a compact string of characters used for identifying an abstract or physical resource; it appears in absolute or relative form; URI references are not allowed to contain characters such as all non-ASCII characters and excluded characters listed in IETF RFC 2396, except for number sign (#) and percent sign (%) and the square brackets; example: http://www.iasb.org/xbrl;

more: IETF RFC: 2396;

use attribute

use is an optional attribute that appears on arcs; its two possible values are "optional" and "prohibited"; "optional" is a default value (that is the value that the attribute is assigned when it is not specified) and represents a relationship that may participate in the network of relations defined in a DTS; "prohibited" indicates that the relationship does not exist; the use attribute is used by taxonomy extension creators to prohibit and override relations defined in linkbases of the base taxonomy;

more: XBRL Spec:;



the term versioning in XBRL relates to issues and problems that occur when implementing changes to an existing taxonomy; any changes to a taxonomy may particularly affect extensions that are based on it; versioning aims to help applications and people involved in taxonomy building and instance creation to tack these changes; first set of requirements concerning this issue was released by XBRL International on 1 October 2002; the second edition called the Taxonomy Life Cycle is at the stage of Internal Working Draft;

more: Versioning Requirements 2002-10-01;


weight attribute

weight is a required attribute on calculationArc elements; it must have a non-zero decimal value; for summation-item arcs, the weight attribute indicates the multiplier to be applied to a numeric item value (content) when accumulating numeric values from item elements to summation elements; a value of "1.0" means that 1.0 times the numeric value of the item is applied to the parent item; a weight of "-1.0" means that 1.0 times the numeric value is subtracted from the summation item; there are also rules that are applied to the calculation of elements possessing opposite balance attribute values ('credit' and 'debit');

more: XBRL Spec:;



XBRL stands for eXtensible Business Reporting Language; it is an XML dialect developed for business and financial reporting purposes by a non-profit consortium XBRL International which has members from 400 companies and institutions that represent finance and IT sector organizations from all over the world; learn more from our Fundamentals of XBRL section or visit the XBRL International website;

xbrl element

an xbrl element is usually the root element of instance documents; in files, it serves as a container of data in XBRL format; first and foremost it contains an element that refers to the schema (schemaRef), provides contextual information (context and unit) for included facts and may provide them with footnotes (footnoteLink);

more: XBRL Spec: 4.1;

XBRL Specification

an XBRL Specification defines the rules and fundamentals of the language; it is designed to communicate information to IT professionals who develop applications and tools intended to be XBRL compatible and to a lesser extent is assists taxonomy creators; to find out more and obtain the latest version of the XBRL Specification visit XBRL International website;


XLink (XML Linking Language) is a language for creating hyperlinks in XML documents; it works in a similar way to the <a> element and its href attribute in HTML; to get access to its features there should be an XLink namespace declared usually at the top of the document ("http://www.w3.org/1999/xlink");

more: XLink W3C Recommendation from 27 June 2001;


XML stands for Extensible Markup Language; it was developed by W3C (World Wide Web Consortium) to describe and carry data by allowing users to define their own tags (in contrast to HTML where the tags are predefined); this data (tags) is characterized using a Document Type Definition (DTD) or XML Schema which are self-descriptive;

more: XML 1.1 W3C Recommendation from 04 February 2004;

xmlns attribute

an xmlns attribute is used to declare namespaces and their prefixes; in XBRL it is usually used on root or top level elements (schema, linkbase, xbrl);

XML Schema

an XML Schema defines the structure and the content of the XML documents that refer to it, by defining, in particular, the elements and attributes and providing information about their type and possible content;

more: XML Schema W3C Specification and Development;


XPath was developed to help finding information in XML documents; it is mainly used in XSLT to navigate over elements and attributes; XPath provides a set of functions that allows specific actions to be performed on XML data;

more: XPath 2.0 W3C Recommendation from 3 November 2005;


XPointer supports XLink by providing solutions to locate specific fragments of the XML document; its full name is XML Pointing Language; XBRL uses two specific XPointer schemes: the element pointer (works by counting) and the shorthand pointer(works by referencing to an id);

more: XPointer Framework W3C Recommendation 25 March 2003;


XSLT stands for eXtensible Stylesheet Language Transformations and has been developed to facilitate conversions of XML documents into other XML documents or into other formats (e.g. XHTML); to perform these transformations, XSLT uses XPath expressions;

more: XSL Transformations 1.0 W3C Recommendation 16 November 1999;