"seller", in the case of a sale by an agent, means the principal.
"unobtained shares" means shares of a class that a seller has agreed to sell but over which he or she does not, at the time of the sale, have a presently exercisable and unconditional right to vest in the buyer.
where:
"PS" (number of unobtained shares Previously Sold) means the number of unobtained shares previously sold in sales that have not been completed at the time of the sale.