right-hand rule
List of: Glossary Items
Subjects: Work Coordinate Systems
Contents: Glossary

Point your right hand thumb up along the z-axis away form the WCS origin, and curl your fingers around the axis. Your fingers point in the direction of positive x-to-y rotation.
PDF/GLOSSARY/01GLOSS.PDF
HTM/DATA/ACIS/GLOSSARY/01GLOSS/0300.HTM