The CDU uses a three-tiered system to classify whether an item is legal. The categories are: * Unrestricted: Relatively innocuous, with widespread legitimate need. few controls on distribution. Requires basic operator's credentials for items such as vehicles, starships and firearms. * Restricted: Dangerous if misused, but with legitimate uses. Background check and/or credentials/permits required are required to legally possess, and the would-be owner is generally required to demonstrate legitimate need. If acquired outside the CDU, the item must be registered with the appropriate authority. * Prohibited: Generally dangerous. Most uses are nefarious. Distribution is interdicted. Legal possession requires specific government permission (eg a Letter of Marque, designation as a milit