Feature summary (what you would like to be able to do and where):

You should have the ability to require a statement on a type of entity

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):

Requiring statements like the License on a MediaInfo entity for a File on Commons.

Benefits (why should this be implemented?):

Right now licenses are template-based and can easily be removed by vandalizers. Making it required in Structured Data as well as making sure it is a valid license can help editors easily choose licenses and data consumers reliably query for license data about Files on Commons.