Crystallography Online: the website of the International Union of Crystallography

> It would help if Howard could supply us with good definitions of all thet terms so we all understand what we are talking about. 

   INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY
   ORGANIC CHEMISTRY DIVISION
   COMMISSION ON NOMENCLATURE OF ORGANIC CHEMISTRY
   COMMISSION ON PHYSICAL ORGANIC CHEMISTRY

   Basic Terminology of Stereochemistry

   (IUPAC Recommendations 1996)

   http://www.chem.qmul.ac.uk/iupac/stereo/

   The definitions used in this glossary are identical to those in the 
published document, see G.P. Moss Pure and Applied Chemistry, 68, 
2193-2222 (1996)