If you specify a CONTROL statement, PROC SURVEYSELECT sorts the input data set by the CONTROL variables before selecting the sample. If you also specify a STRATA statement, the procedure sorts by ...

In programming, a variable that keeps track of the number of iterations of a process. Its value is incremented or decremented with each iteration, and it is compared to a constant or other variable to ...

Variable names are alphanumeric but must start with a letter. The length of a variable name is limited to thirty-two characters for non-SAS data set variables Model variables are declared by VAR, ...