1. A document processing method, comprising the steps of: acquiring a template consisting of at least one semantic item, wherein (i) candidate values of said semantic item and relations among said semantic items are associated with machine-processable semantic codes, and (ii) said template is associated with a corresponding natural language expression mode; receiving an input value for said semantic item generating a machine-processable document comprising (i) said machine-processable semantic codes based on said input value, (ii) the relation among said semantic items and (iii) the machine-processable semantic codes as associated; and generating a natural language document comprising said input value based on said input value and said natural language expression mode.