The CDS XML Schema Version Number Format
The use of XML was mandated by the e-Government Interoperability Framework (e-GIF) programme as the standard to be used for messaging by government organisations and has accordingly been adopted by the NHS.
The CDS XML Schema adopts version numbering techniques in line with published e-GOV best practice guidelines. All schema components are version numbered and date qualified; the following is an example of the adopted format:
CDS XML Message Root
Example: V6-0-2007-03-01 (Note that dash separators are used).
[Schema Filename] + [Major Version Number] + [Minor Version Number] + [Version Date]
VERSION NUMBER ELEMENT
EXAMPLE AND NOTES
|XML Schema File Name||As allocated by Information Standards Delivery,|
|Major Version Number||A maximum of 3 characters|
without leading zeros
|Minor Version Number||A maximum of 3 characters|
without leading zeros
The Major Version Number:
This is incremented when fundamental change has taken place such as:
- Major addition / deletion / change of XML Schema business functionality
- Major change to the technical design of the schema
- Re-alignment of the XML Schema Version Number after cumulative changes
This is incremented for all XML Schema changes not warranting a Major Version Number increment (as above).
- Minor changes to XML Schema business functionality
- Minor changes to the XML Schema data structures that are not upwardly compatible*
- Addition and/or deletion of data items that are not upwardly compatible*
- Changes to data item facet definitions that are not upwardly compatible*
This may be adjusted as a defined reference point for a no risk XML Schema release to reflect minor changes and corrective releases.
- Minor changes to the XML Schema data structures that are upwardly compatible* for instance the addition of an optional data item.
- Changes to data item facet definitions that are upwardly compatible* for instance the addition (but not the deletion) of code values to a data item enumeration list.
- Interim development versions, released for information only
* Upwardly Compatible:
Minor changes and adjustments to the XML Schema which introduce little or no risk of increased data rejection are deemed upwardly compatible.
For example, corrective adjustments, which align the XML Schema to the authorised NHS Data Standards as published in the NHS Data Model and Dictionary often fall within this category.
The XML Schema Date:
All XML Schema releases have a designated SchemaDate XML Attribute.
XML Schema Version Control - The Schema Root:
The schema root is the single entry point to the XML Schema and XML Attributes for the following are validated: