Is it safe to talk about punctuation again? Eight years ago, Lynne Truss’s best-selling “Eats, Shoots & Leaves” took, in the words of her subtitle, a “Zero Tolerance Approach” to the subject. Although Truss’s focus on errors drew the ire, if not the fire, of grammarians, linguists and other “descriptivists,” her book was, for the most part, harmless and legitimate. Still, it overlooked a lot. Maybe more than any other element of writing, punctuation combines rules with issues of sound, preference and personal style. And as Truss didn’t adequately acknowledge, even the rules change over time.