Altova web site: Text and Flat File Mapping
FlexText is a MapForce module which enables you to convert data from non-standard or legacy text files of high complexity to other formats supported by MapForce. While XML files have a schema or a structure from which MapForce can derive the schema, this is not the case of text files, especially when they have a complex and unique structure that does not consistently fit into CSV or fixed-length field patterns. Moreover, sometimes you need to extract only portions of useful data from a legacy text file. FlexText solves these problems by helping you define and test visually, in real-time, the rules, or the template, according to which text data must be split down into mappable items. A FlexText template essentially defines the structural model of your custom text data, according to criteria you specify, for the purpose of mapping it to other formats.
Once you define a FlexText template, you can add it to the MapForce mapping area as a source or target component, and thus map complex and non-standard text data with any other format supported by MapForce. FlexText template files have the .mft (MapForce FlexText) extension. You can reuse the same FlexText template in multiple mappings, to process any number of text files.