The version number for improved versions of WordPress might not follow a strictly monotonic or periodic numerical (or in the case of test releases, alphabetical) sequence, since the version numbers reflect relative progress, and the changes made to existing or previous versions. So, for example, since v1.2 is a majorly revamped version of v1.0 (with about 60% of the code having been touched), 1.1 was ’skipped’ along the way.