In Crucible, Administrators can control whether users can use the Author Mapping setting to map their own Crucible usernames to repository committer accounts or not. By default, the setting allows users to set their own mappings.
If you wish to lock down the mappings for security or audit reasons, this setting lets you restrict all management of mappings to Crucible administrators only.
To do this, click Administration in the footer of the Crucible interface and then Authentication (under 'Security Settings') in the left navigation bar. You can set User Managed Mappings either On or Off. The setting is applied immediately.
Screenshot: User Managed Mappings