If you have seen a specific reference to a "Lab Manual exclusive," it's most likely a resource from the community, not an official part of the game that requires an exclusive key. If you share where you saw this, I could help you track down its origin.
The component often refers to special bundles that include advanced post-launch software updates, scenario editors, or premium in-game content only available through the official Capitalism Lab website. 2. The Importance of a Genuine Registration Key registration key for capitalism lab manual exclusive