The ratio of the percentage of one @E02069@ in a mixture to that of the other e.g. \(70\left(\!+\!\right)\,\colon\,30\left(\!-\!\right)\).
Source: PAC, 1996,
68, 2193. (
Basic terminology of stereochemistry (IUPAC Recommendations 1996)) on page 2207 [
Terms] [
Paper]