I am creating multiple lists in SharePoint that use each other for "lookup" columns. Here is the situation and what I am doing. It is a very expansive inventory list of Equipment Racks. I have created a list of gear manufactures, a list of model numbers that use the manufacturer list as a lookup. I also have a document library with user manuals for these items. Since many racks use the same pieces of gear I would like to somehow link the manual to the list item in the model list. That way each time the model number is selected in each Equipment rack list there is access to the same file (User Manual) in the document library. I don't want to attach a separate User Manual file to each list item AND upload the User Manual to the Document Library. If the manual gets updated then both places would need to be updated and that isn't efficient. Any ideas or best practices would be very helpful.