Every side-by-side assembly must have a version. Each assembly version is associated with a version number having four parts separated by periods: major.minor.build.revision. If a change is made to an assembly making it incompatible with existing versions, the major or minor parts of the version number must be changed. A version number that changes only in the build or revision parts indicates that the assembly is backward compatible with prior versions.

The version must be specified in <assemblyIdentity> elements of manifests. Use the four-part version format: mmmmm.nnnnn.ooooo.ppppp. Each of the parts separated by periods can be 0-65535 inclusive.

Send comments about this topic to Microsoft

Build date: 6/4/2009