MapTiler Toner GL Style
For a browsable electronic map the copyright notice must appear in the corner of the map:
For printed and static maps a similar attribution must be made in a textual description near the image, in the same fashion as if you cite a photograph.
Exceptions to attribution requirement can be in a written form granted by MapTiler AG (email@example.com). The project contributors grant MapTiler AG the license to give such exceptions on a commercial basis.