Data Extraction Instruction File, also called as MAP file, is a standard XSLT command file, which transforms target Web pages and extracts data from them and serializes the harvests into XML files, i.e. Data Extraction Result Files.
The instruction files are stored in DataStore's folder $CATALINE/work/DataStore/context/extraction/config/<theme_name>/ whose names are suffixed by .gem.xslt. Because the files contains standard XSLT commands, the structures of them are not stated further.
