Each document version is assigned a number that reflects whether the document is Major or Minor version. This number is automatically assigned and changed by the Content Engine whenever a versioning action, like Checkout, Promote or Demote, takes place that changes the document's version status.
The version number is unique in the Document's version series and is actually comprised of two properties—the Major version number and the Minor version number. These properties are described in Versioning properties.
The numbering rules are fairly simple:
As you can see, these two numbers can be joined into what looks like a single number. Enterprise Manager and application such as Workplace sometimes display these numbers joined together with a decimal divider, with the Major number coming before the decimal and the Minor number after. In other places like the list of properties in the object's property grid, the two properties are listed separately.
If a new document is first checked in as a Minor version, its version number becomes 0.1. The next version in this series would be 0.2 if a Minor, and would be 1.0 if it is checked in as a Major.
If a new document is first checked in as a Major version, its number would be 1.0. The second version in this series would be 2.0 if a Major, and would be 1.1 if it is checked in as a Minor.
A document in the Reservation state is always a Minor document and has a Minor document number. For example, if you check out a document numbered 2.0, the resulting Reservation version will be numbered 2.1. If you check out a document numbered 2.1, the resulting Reservation version will be numbered 2.2 (because a Reservation is always a Minor).
It is on checkin that users can decide whether to check in the Document as a Minor or as Major. A Reservation's number will therefore stay the same if it is checked in as a Minor, and will change if it is checked in as a Major. For example, a Reservation numbered 2.1 will still be numbered 2.1 if it is checked in as a Minor version. If the same Reservation numbered 2.1 is checked in as a Major version its number will change to 3.0.
The sequencing tables in the topics on two-level versioning and one-level versioning provide extensive examples of version numbering.