The spatial arrangement of two conjugated double bonds about the intervening single
bond is described as s-cis if synperiplanar and s-trans if antiperiplanar. This term should not be applied to other systems such as N-alkyl amides (use E/Z or sp/ap).
Source:
PAC, 1996, 68, 2193
(Basic terminology of stereochemistry (IUPAC Recommendations 1996))
on page 2217
