ModSnmp Manual v3.14 - 5.3. Deleting Device Types
Devices can be deleted using the Device Types page:
To delete a device type, select the device type and then click the Delete button.
To delete several device types, select them by clicking on them while holding down the control key, and then click the Delete button.
To delete all device types, click the Delete All button.
A device type cannot be deleted if it is in use by a device definition.