Business reporting is fast changing in a dynamic global economic environment. Any change in business reporting has an impact on the underlying XBRL taxonomy as well.
XBRL facilitates business reporting in a digital format that can be understood by computers. The base for any XBRL reporting framework is the underlying taxonomy. Taxonomy defines the business reporting requirement and associated logic like business rules, references to authoritative literature, etc. Taxonomies are updated from time to time to incorporate new business requirements or new specifications issued by XBRL International (XII). Taxonomies are also updated at times to align with global reporting practices or to fix certain errors (bugs) that might have crept in.
Any change in taxonomy is bound to impact the entire supply chain of XBRL reporting too. Some major impacted areas are related to XBRL instance creation software and reporting platforms, data migration, and data consumption. A change in taxonomy would have an impact on the stakeholders and it becomes necessary to communicate to the stakeholders the change logs concerning the new taxonomy.
Versioning Linkbase: To keep track of Versions
Conventionally, the change log for taxonomies is documented in a free-flow format, often supported by visual clues. The change log prepared for IFRS taxonomies is a good example of highlighting the changes. However, understanding the changes is not only for the taxonomy users but also for the computer applications as well. To answer this need, XII has released the specification for ‘versioning”. It is commonly referred to as Versioning Linkbase or Versioning Report. This document records the differences between two taxonomies in a standard and computer-readable manner.
Let us look at some of the building blocks of Versioning Linkbase. The versioning linkbase is based on the XML syntax. This linkbase requires every change to be classified according to its nature. As briefly mentioned above, changes can be on account of
- Change in reporting or disclosure needs (referred asto bua siness category)
- Change on account of including new specification (referred asto tea chnical category)
- Change to fix errors (referred asto errata)
If we look at all the changes, then it might result in adthe dition or deletion, change or renaming of taxonomy arartifactsThe versioning specification consists of many modules, each having its function. There are modules that can be used for describing schema changes. For example, the addition of new elements, deletion of existing elements, or change in attributes for some elements. Similarly, there are modules designed for identifying the changes that are made in link bases. Using these modules, it is possible to specify if any specific relationship or entire hierarchy of relationships has been added or deleted in the extended link role. Further, the changes in attributes of the relationship like weight, order, use e,tc. can also be specified. In the case of dimensional relationship, there is a provision to highlight the changes in the primary concept, dimension, and domain member combination.
The advantage of using versioning specification is not only to track the taxonomy changes logs in sta andard manner but also to facilitate and support presenting these changes to business users inin theeast technical manner. The IFRS 2014 taxonomy is one of the recent examples where this versioning specification has been implemented.
This relatively new specification is trying to solve some problems in the world of XBRL and is slowly getting adopted. Though the specification has wide coverage in terms of capturing the types of changes, there is some scope-out areas as well, for the time being.
We encourage all the taxonomy authors and XBthe RL implementation community to follow this specification. In the event, ifthathere anare y suggestions or additional scenarios to be taken care of in versioning specification, please get in touch with XII and also get involved in the working groups so that the additional needs and business requirements are considered and incorporated as well.