Minecraft wiki entry for Version_formats, associated text: Version numbers were re-added during Alpha starting from version v1.0.1. The version format now was a "v" followed by three numbers in the order phase, major, minor. Minecraft was now in somewhat of a complete state, as it had left the "development" stages of Indev and Infdev, and as such the "phase" counter was changed to "1". An optional underscored bug fix patch was also used in this development phase. For example, Alpha v1.2.3_02 is the second bug fix patch ("_02") for the third minor revision (".3") of the second major version (".2") of Alpha.