14. The system of claim 1 , comprising a creator module to create the base file of the document class, the creator module being to: compare delta-differences between a group of sample documents belonging to the document class; summing the delta-difference for each of the sample documents of the group; and selecting the base file from the sample documents, wherein the base file has the lowest sum of delta-differences.
14. The system of claim 1 , comprising a creator module to create the base file of the document class, the creator module being to: compare delta-differences between a group of sample documents belonging to the document class; summing the delta-difference for each of the sample documents of the group; and selecting the base file from the sample documents, wherein the base file has the lowest sum of delta-differences. 16. The system of claim 14 , wherein the creator module is to replace at least one of the sample documents with a requested document specified by a user.