PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT NOTE = "Description of the contents of the EXTRAS directory" PUBLICATION_DATE = 2013-08-27 END_OBJECT = TEXT END CONTENTS OF THE EXTRAS DIRECTORY The EXTRAS directory contains files which may facilitate the use of the data in the current volume, but which are not actually required for the use or understanding of those data. EXTRINFO.TXT The file you are now reading. Identifies and describes the function of each file in the EXTRAS directory. ZMASK_PENETRATING.TXT A Z-mask table. These tables are described in the SIS document found in the DOCUMENT directory of this volume. ZMASK_STOPPING.TXT A Z-mask table. These tables are described in the SIS document found in the DOCUMENT directory of this volume.