Knowledge managers frequently discuss the number of document categories (types) in the document management system. 

The accepted wisdom is that about a dozen types is right. Even then, lawyers often will not select the appropriate type. Some firms started with 100+ types and pay the price of confusion and mis-use. I’m at a conference now and a speaker just told a great story illustrating this. His firm has 100+ types, including one called “Quit” which was created for a T&E practice that wanted quitclaims categorized. When the KM department looked at the documents in this category, they found 40 letters of resignation!