If setting the Versionspec file directive is not enough for comparing package versions, you can use an Epoch directive. For example, you can use Epoch to resolve upgrade path issues that occurred because of the upstream change in a version numbering scheme in an incompatible manner.

Epoch is a numeric field. If you assign a value to Epoch, it adds a qualifier that RPM uses when comparing package versions. Not having the Epoch directive listed in a spec file means Epoch is not set. This is contrary to the common belief that not setting Epoch results in an Epoch of 0. However, for processing purposes, if you do not set Epoch, RPM treats it the same as if the Epoch was set to 0, and vice versa.