d.s.p.l.

D.s.p.l. tells you that the person left no children born to a lawful marriage. It does not say there were no children at all; a child born outside marriage could exist and simply not count as an heir.

It is found in pedigrees and inheritance notes, where legitimacy decided who could inherit. If you suspect a child was left out, look at bastardy bonds, guardianship records and the person's will, which might still name the child.