We are using SP2013 on-premise. On a site collection there is a document library. There are several users with "Manage Permission" permission. Based on their need, they will change the permission on individual documents (permission inheritance is broken).
However, when they try to share the document to other users, the default permission level choice is always "contribute". Can we change the default choice to be "read only" and the "send email invitation" always off? It is because the permission level part is always hided. User need to click the "SHOW OPTIONS" to see the level choice. Users may grant the contribute permission level by mistake (and send email out).