The following was added to the Commentary C4.3.5.3:
Interpolation of C(ub) is permissible for intermediate stud spacing (e.g. for 19.2” stud spacing C(ub) = 0.52 for sheathing nailed with ... 12” nail spacing at intermediate framing).
Shearwalls had been using the Cub values listed in Table 4.5.5.3 for 20" spacing when 19.2" was the selected stud spacing, or 0.6" for 6" intermediate spacing and 0.5" for 12" intermediate spacing. These have been changed to 0.64 and 0. 52, respectively.