Pretty famous example: https://en.wikipedia.org/wiki/Venetian_glass#Island_of_Muran...
> Glassmakers were not allowed to leave the island without permission from the government. Leaving without permission, or revealing trade secrets, was punishable by death
Though importantly this was enforced by state.
Pretty famous example: https://en.wikipedia.org/wiki/Venetian_glass#Island_of_Muran...
> Glassmakers were not allowed to leave the island without permission from the government. Leaving without permission, or revealing trade secrets, was punishable by death
Though importantly this was enforced by state.