Admin - Role Settings

Drupal has the concept of 'defined roles' that determine the behavior of a user. Roles can be used to allow or deny access to applications, and to specific tasks within an application. In the case of dbFM, roles can also be used to restrict access to individual files See Access Privileges).

Apart from access privileges the different drupal roles can be tailored in the following ways from the Admin Roles form:

Exceptions to excluded file extensions.

On the main admin screen you can define a list of excluded file extensions.  - perhaps you might want to block users from uploading .exe files and .bat files so these would be listed on the default list.
The role settings allow you to override the defaults. For example you might want your IT administrators to be able to upload any file types, in which case you would override the default settings by entering +exe +bat in the exceptions list for the ITRole.
Alternatively you might want to further limit the types of files that your marketing team can upload. In this case you preceed the file extension with a minus. So for the marketingRole you might add -mpg -avi -wmv -swf to the excluded file extensions, to prevent them uploading certain media files. That should work - in point of fact it will work for users who only have a marketting role. Users with more than one role will not be blocked from uploading those file types. Every user who logs in has the role 'authenticated user', however since there is no relationship between a user and the 'authenticated user' role in the users_roles table the code ignores this.

Maximum filesize per upload

The main admin screen allows the default maximum file upload size to be defined. If a value is filled in on the Role Settings screen this will override the default. So you might have a default limit of 1Meg yet change the setting for IT administrators to 25Meg. As with the excluded file extensions above, users may have more than one role. If this is the case they will inherit the maximum filesize allowed for any of their roles.

Enable Node Attachments (check box)

The main admin screen gives the following options for attachments: Attachments Off, All Roles allowed to add attachments, Restrict attachments to specific roles.
If (and only if) the third option is chosen on the main admin screen, then this check box has an affect, enabling or disabling the ability to attach dbFM files to nodes.