I have been questioned the upload on Wikimedia Commons of internal documents from a museum because they are not educational.

I think it is a tricky issue since all archives are made of internal documents from institutions (and it is not easy to define what is educational or when it will be educational).

i opened a discussion on wikimedia commons about it https://commons.wikimedia.org/wiki/Commons:Village_pump#Internal_documents_from_an_institution

best 

iolanda/iopensa