protector package adds an additional level of content management of that of simple package selection. 
The user role (formally 'group') is taken as this level and only users assigned to the selected
role will be able to see the content in lists and view it.

An additional facility added to protector for central management of attachments although this is not  
required for protector to work. 
mime.flatdefault.php uses /storage/attachments/<content_id%1000./<content_id> for all content, rather 
than filing them under each user. This is appropriate for sites where multiple users all add content
to a central set of documentation.