3.3.4.5 Version Number Update
GPO container version: The user GPO version part of GPO container version MUST be incremented if the user policy settings are being modified. The machine GPO version part of GPO container version MUST be incremented if computer policy settings are being modified. If, after the increment, the user GPO version or machine GPO version is 0, the value MUST be set to 1.
GPO file system version: The user GPO version part of GPO file system version MUST be incremented if the user policy settings are being modified. The machine GPO version part of the GPO file system version MUST be incremented if the computer policy settings are being modified. If, after the increment, the user GPO version or machine GPO version is 0, the value MUST be set to 1.
If the user policy settings are being modified then both the GPO container version and the GPO file system version for the user GPO version part MUST be updated as mentioned previously.
If the computer policy settings are being modified then both the GPO container version and the GPO file system version for the machine GPO version part MUST be updated as mentioned previously.
Issue a GPO Property Update event (section 3.3.5.3). This message MUST specify the versionNumber attribute set to the value of the GPO container version in the modifyRequest portion of the GPO Property Update event. The GPO Property Update event itself issues a GPO File System Version Update (section 3.3.5.4) that MUST specify the GPO file system version.