Limiting Edit Privileges for All Action Items
You can limit the edit privileges on all action items, preventing the action item assignee from updating the following fields:
• Name
• Description
• Assignee
• Due Date
• Priority
To limit the edit privileges for all action items, a site or organization administrator can set the > preference to Yes using the Preference Management utility from either the Site 
> page or the Organizations 
> page for your organization. Assignees will not be allowed to update the fields listed above for any action items.
> page or the Organizations > page for your organization. Assignees will not be allowed to update the fields listed above for any action items.