Yup. More precise, it has the same specificity as the selector it is negating in its "parameter" (which must be a "simple" one, not compound). My favourite CS

Yup. More precise, it has the same specificity as the selector it is negating in its "parameter" (which must be a "simple" one, not compound). My favourite CSS bruteforce hack [1] for boosting specificity exploits this: *:not(#\0):not(#\0):not(#\0) {} /* three ID strong anything */ [1] Never used it in meaningful context, actually.