All my maps are under CREATIVE COMMONS ATTRIBUTION-SHAREALIKE 4.0 INTERNATIONAL
If you don't understand what the license means, don't worry, I'll explain here.
You can SHARE (copy and redistribute the material in any medium or format for ANY purpose, even commercially) and ADAPT (remix, transform, and build upon the material for ANY purpose, even commercially).
Attribution: You MUST give appropriate credit, provide a link to the license, and indicate if CHANGES were made. You may do so in any reasonable manner, but NOT in any way that suggests the licensor (me) endorses you or your use.
ShareAlike: If you remix, transform, or build upon the material, you MUST distribute your contributions under the SAME license as the original (Creative Commons Attribution-ShareAlike 4.0 International).
You DO NOT have to notify me if you use my maps. I'd appreciate it if you did (I like to see where my maps are being used), but by law, you aren't required to.