From Post-Apocalyptic RPG wiki
This article explains how the agreed upon licenses that we use for PARPG affect the work of the graphics department. Make sure to also check out the License article that covers the license-related aspects that affect the project as a whole.
Copy/paste from graphics department starting page
Be sure to use only content that is compatible with our chosen License. If you're contributing as 3d artist, make sure that the textures you're using are properly licensed as well.