Our all new and improved licensing policy updates our non-code licence to CC-BY-SA 4.0
https://community.kde.org/Policies/Licensing_Policy
"Content on collaborative edited websites such as wikis must be licensed under the Creative Commons Attribution-Sharealike 4.0 International or compatible licence."

Please update all the WikiToLearn wikis to CC-BY-SA 4.0

e.g. https://it.wikitolearn.org/Project:Copyright

(CC-BY-SA 3.0 can automatically be changed to CC-BY-SA 4.0)