All ddcToolbox products use a version number that correspond to the release date of the software. This makes for simple calculations of which versions are supported under your current technical support and updates coverage. The version number is the date of the release in the YY.MM.DD format.
A release date of ddcBar on January 12, 2020 would have a version number of 20.1.12. A release of the ddcToolset on November 6, 2019 would have a version number of 19.11.6. In some cases a new download will use the same version number but further identified with a suffix number such as r1, r2, r3, etc. These are updates to the installer package for that product version and should be downloaded and installed if available.
To find what releases are covered by your current support/upgrade period just convert the last day of your coverage to a version number. Any release matching that version as well as earlier (lower version numbers) can be installed and will be recognized by your software license.