The OBS= and FIRSTOBS= are system options used to specify the first and last observations read from input datasets. For instance, if I wanted to process only observations 4 through to 7 in the ecprg193 library and country dataset, I could write the following:

libname ecprg193 '/home/marija/ecprg193';
options firstobs=4 obs=7;
proc print;


For more information, see: FIRSTOBS= Data Set Option:

OBS= Data Set Option: