20. A system as recited in claim 18 , the acts further comprising: training the classifier to categorize the documents into the multiple classes prior to the categorizing.
20. A system as recited in claim 18 , the acts further comprising: training the classifier to categorize the documents into the multiple classes prior to the categorizing. 21. A system as recited in claim 20 , wherein the training the classifier comprises training the classifier using a first set of training documents that include one or more specified criteria and a second set of training documents that do not include at least a portion of the one or more specified criteria.