Suppose a spreadsheet contains a potential list of elements names and one only wishes those element names associated with nonzero data or yes such as the section below from gdxxrwss.xls.
One would read this with the statement Gdxxrwread.gms
$call "Gdxxrw gdxxrwss.xls set=i2 rng=sheet1!a5:d6 cdim=1 values=yn"
and the resultant i2 set will only have the elements boats and watercraft since the other two elements are associated with a blank or a no.