We give part numbers to our assembly instruction manuals so that we can keep track of the current revision, add them to BoMs, etc.  However, we don't want to keep track of inventory levels for these items.  We just want to have the part number for the correct manual be included on the BoM for an item, and only one (1) manual should be included with a kit of parts for a manufacturing order, regardless of the quantity of items to be assembled.  For example, if we have two manufacturing orders open for ThingA, with quantities of 50 and 100, we'd still include only one manual with each order.  How should this type of arrangement be set up in OpenERP?