Computer methods, apparatus and articles of manufacture therefor, are disclosed for developing a region-matching transducer for marking language data having delimited strings. The region-matching transducer defines one or more patterns of one or more sequences of delimited strings, with at least one of the patterns defined in the region-matching transducer having an arrangement of a plurality of class-matching networks. The plurality of class-matching networks defines a combination of two or more entity classes from one or both of part-of-speech classes and application-specific classes. The region-matching transducer has, for each of the one or more patterns, an arc that leads from a penultimate state with a transition label that identifies the entity class of the pattern, and shares states between patterns leading to a penultimate state when segments of delimited strings making up two or more patterns overlap.