Which sources count?
Primary sources only. For how WinDirStat behaves, that means the source code, installer definition and English language file at a named release tag on windirstat/windirstat. For versions and fixes, the official changelog, linked to the entry for each version. For licensing, supported Windows versions and official download channels, the project's README. For files, sizes and hashes, the GitHub release data; for winget, Microsoft's public manifests. Comparisons with other disk space analyzers cite each vendor's own product page, and prices are never quoted from memory.
How are defaults and menu names verified?
By reading the code of the release the pages describe, currently 2.9.0. A default, such as whether duplicate detection starts on, is taken from the line that declares it, a keyboard shortcut from the accelerator table, and a menu label from the language file that displays it. Each fact is recorded with its file and line in the site's research notes, and the upstream files are listed so a script can tell when they change.
What happens when WinDirStat ships a new release?
A daily job fetches the latest release. If the source files behind the guides did not change, the checked version moves forward automatically. If any of them changed, the page stamps show both versions and an editor re-reads the affected pages against the new source before the stamp returns to normal.
How are corrections handled?
A reported or discovered error is checked against the primary source, fixed on every page that repeats it, and the page's "last verified" date is updated. The contact page lists how to reach the editorial team.