Once documentation achieves association to the project through the Project ID and has a document name (refer to Saving an Electronic Document), it is important to be able to track changes between different versions of it. Take for example that a Project Brief is found to be incorrect and the project team issue a new version of the document. It is important to be able to identify clearly which document is the most current.
This is achieved by using a version control system. The recommended system for document version control follows these basic rules:

For example, the first draft would be shown as D0.01.  When you provide this document to another person it is considered a release (albeit a draft release). This means that become you make any changes you will update the draft version number. In this way, you know that two documents exist.

From the first draft, draft D0.01, if it required another draft it would become D0.02 etc until such time as it became a released version, which would make it version 1.00.  Where a change is significant, the first digit changes to denote a major change in the document, making the version number 2.00.

Future drafts, once a release has been published, would begin with a D and follow the same process, as shown in the table below.