Have the ability to create custom user groups/roles which you can assign to certain users. And to have specific access and ability permissions(such as read, edit, delete pages, upload images, delete images, create pages, comment etc.) that can be assigned to these customizable user groups/roles. Like on MediaWiki: https://www.mediawiki.org/wiki/Help:User_rights_and_groups

Also, have the ability to protect pages, meaning, limit their editing rights to certain user groups/roles, much like on MediaWiki:

https://www.mediawiki.org/wiki/Help:Protected_pages

https://www.mediawiki.org/wiki/Help:Protecting_and_unprotecting_pages