Specialized Administration > Tailoring Business Objects > Object Initialization Rules Administration > Working with Object Initialization Rules > Object Numbering and Versioning > Object Versioning > Types of Versioning Schemes
  
Types of Versioning Schemes
There are four Harvard versioning schemes available for your use:
• A standard alphabetic scheme -- This is the default scheme set in the site context (described in Out-of-the-Box Default Scheme).
• A standard integer scheme -- Version identifiers are assigned starting with 1, incremented by 1, and can reach a maximum of 2147483647.
• A file-based scheme -- Version identifiers are assigned from an XML file that is loaded into the database. The values in the XML file can establish the version identifiers that are used.
• A state-based scheme -- This scheme is an extension of file-based versioning. It involves the use of <seed name> elements within the file-based versioning XML file that then map to the states set up in a life cycle template.
PTC supports the use of the ASME Y 14.35M revision standard for revisions. You can use the wt.series.HarvardSeries.MilSpec properties to set up a versioning scheme that meets this standard, and the out-of-the-box state-based versioning scheme also meets the standard. For details on updating an existing versioning scheme to the standard, see Changing Versioning Schemes.