Hmmmm... that section refers to rigid diaphragms and I've never considered a wood diaphragm to be rigid, but it's possible that for that particular chapter (23) they have defined "rigid" in a different way. I'll need to look into that. Thanks! That helps a lot.
Yes, sorry that was a bit general.
The 97 UBC 2315.1 is what I'm referring to.
I'm trying to find where the above UBC section is in the new IBC code, or rather, how its referred to.