Those incomes by a persons that are subject to full and final discharge of Tax liability comes under PTR. For Example income from Dividinds, Prize bonds etc
It is to ficilitate general public and probably the intention is to enhance investment and economy.
Note Information given are based on Tax year 2004 get Update information seeing Sections 148-156B & 169
One Advise more is never overlook this part of Ordinance CHAPTER-IV COMMON RULES PART I GENERAL(section 66-73)