The variable in the FREQ statement identifies a variable that contains the frequency of occurrence of each observation. PROC SURVEYLOGISTIC  treats each observation as if it appears times, where is the value of the FREQ variable for the observation. If it is not an integer, the frequency value is truncated to an integer. If the frequency value is less than 1 or missing, the observation is not used in the model fitting. When the FREQ statement is not specified, each observation is assigned a frequency of 1.

If you use the events/trials syntax in the MODEL statement, the FREQ statement is not allowed because the event and trial variables represent the frequencies in the data set.