extern const char txtStringsFile[];
extern const char txtURLsFile[];
extern const char txtWindowsFile[];
extern const char txtSystemFile[];
extern const char txtIdxHdrFile[];
extern const char txtTocIdxFile[];
extern const char txtTopicsFile[];
extern const char txtUrlTblFile[];
extern const char txtUrlStrFile[];
extern const char txtGrpInfFile[];
extern const char txtMAP[]; 	  // number to URL mapping
extern const char txtITBits[];	   // InfoType bit storage.
extern const char txtSubSetFile[];   // The subset strings
extern const char txtInfoTypeFile[]; // InfoType and Category storage.