Other than their corporate offices and real estate, they don't own physical assets such as factories to make the products they sell. The real value of their company is their knowledge and expertise to design and market products, not manufacture them. Their physical assets are a much smaller part of their total worth. Since it is impossible to store all the information within a company, particularly the tacit information of the people, knowing where to find more information that can be turned into knowledge is key. The reality is that knowledge is in the individual and not the explicit property that can be captured.
Many times knowing the location of where to find more information is all someone needs.
Creating a knowledge map can be as simple or as complex as you want it to be. The available resources and the value that a company places on knowledge management will be a determining factor. Although it would be ideal to have everyone in a company enter into a computer everything they know about anything that may in anyway relate to a company's business. By the time most things are identified and captured, it will be outdated and unless. So instead of capturing the information, just provide a pointer to where the information is located.