https://doi.org/10.1351/goldbook.S05976
A prefix to specify
configuration
(absolute or relative) or
conformation
. For example
R, S
;
r, s
;
P, M
;
Re, Si
;
E, Z
;
ap, sp
; etc.
Source:
PAC, 1996, 68, 2193. (Basic terminology of stereochemistry (IUPAC Recommendations 1996)) on page 2218 [Terms] [Paper]