Sources
The collection keeps only videos with a traceable original page and a documented basis for reuse: a free license or Public Domain status. If that basis cannot be verified, the item is not published.
Wikimedia Commons
The starting point for the first routes: each file has a page, history, author details and a free license.
YouTube Creative Commons
Used carefully and case by case: metadata is saved, the license is checked, and the creator is credited.
Internet Archive and Public Domain
Availability on Internet Archive is not treated as a license by itself. Each archive item needs its own license marker or a documented Public Domain basis; any jurisdiction limit is stated on the item page.
What each item page shows
The video page lists the source, creator when available, license or rights status, a link to the usage terms, and ready-to-use attribution. This makes the basis independently verifiable.