l 

https://doi.org/10.1351/goldbook.L03422
  1. An obsolete prefix for (−)-,
  2. For like and unlike @D01679@
    See: l, u
Source:
PAC, 1996, 68, 2193. (Basic terminology of stereochemistry (IUPAC Recommendations 1996)) on page 2211 [Terms] [Paper]