Well, what the KB site template did was to add a text field to the document library called “Name” in conjunction with an event handler that would ensure that the value of this field always contained the actual name of the file.
As wiki articles were created or modified, the event handler would always ensure that the Name field contained the right value.
When each of the items from the other list are added to the drop-down list, some text value from the other item needs to be displayed here that uniquely identifies the item. For example, let’s say that you are adding a lookup field that is going to be used to select someone from a list of contacts.
Using the Zip Code as the field that is displayed in the drop-down list isn’t likely to be very helpful.
So I created a sandboxed solution that contains a reusable implementation of this concept.
But if we're using a multi-value lookup field to choose a document from a document library, what was the field that was used as the lookup field?
The problem we have is when the “other” list is a document library.
Which field should you choose for the lookup field to display?
Now, the way that the KB site template did this was specific to this site template and isn’t really reusable in other site templates.
The concept is reusable but the specific implementation in that site template isn’t.
I’m still trying to find someone that can explain that to me. Ok, so now we can (finally) get back to the Knowledge Base site template that I was looking into and how it solved this problem.