The biserial correlation measures the strength of the relationship between a binary and a continuous variable, where the binary variable has an underlying continuous distribution but is measured as binary. If the binary variable is truly dichotomous, then the point biserial correlation is used. The rank biserial correlation measures the strength of the relationship between a binary and a rankings (ordinal) variable. Although neither PROC CORR nor PROC FREQ computes these correlations directly, you can use the BISERIAL macro (SAS Note 24991) to compute them.