Q. The rules in CMOS 9.63 for abbreviating number ranges do not seem to be followed in one of the examples for a range of folio pages in 14.54: “fols. 176r–177v” (for the front and back of two consecutive leaves). Why isn’t “fols. 176r–77v” preferred? Thanks for your time and clarification.
A. In the abbreviated range 176–77, there’s little chance that a reader might think you’re referring to pages 176 and 77. But in 176r–77v, the intervening r makes it more likely that “77v” could be mistaken for a reference to the verso of page 77. So our editors decided to repeat the hundreds place for clarity. We’ll consider adding this exception to our rules for abbreviating inclusive numbers—along with any others that might be warranted—in a future edition of CMOS.