In chemical nomenclature, a descriptor is a notational prefix placed before the systematic substance name, which describes the configuration or the stereochemistry of the molecule.[1] Some of the listed descriptors should not be used in publications, as they no longer accurately correspond with the recommendations of the IUPAC. Stereodescriptors are often used in combination with locants to clearly identify a chemical structure unambiguously.
The descriptors, usually placed at the beginning of the systematic name, are not taken into account in the alphabetical sorting.