Within Reporting Services 2008 the "Configure item-level role definitions" link is no longer available.
In RS2008 you have to connect with SQL Server Management Studio 2008 to your Reporting Service server. Than you can find the rol definitions under Security -> Roles.
However you can adjust a role within SQL Server by adjusting the roles table in the ReportServer database. The field TaskMask has 16 digits, every digit has its own description. See the description in order of appearing of the digit.
- View and modify security settings for reports, folders, resources, and shared data sources.
- Create linked reports and publish them to a report server folder.
- View reports and linked reports in the folder hierarchy; view report history snapshots and report properties.
- Create, and delete reports; and modify report properties.
- View resources in the folder hierarchy; and view resource properties.
- Create, modify and delete resources, and modify resource properties.
- View folder items in the folder hierarchy; and view folder properties.
- Create, view and delete folders; and view and modify folder properties.
- Create, view, and delete report history snapshots; and modify report history properties.
- Each user can create, view, modify and delete subscriptions that he or she owns.
- View, modify, and delete any subscription regardless of who owns the subscription.
- View shared data source items in the folder hierarchy; and view data source properties.
- Create and delete shared data source items; and modify data source properties.
- View models in the folder hierarchy, use models as data sources for a report, and run queries against the model to retrieve data.
- Create, view, and delete models; and view and modify model properties.
- Reads report definitions