Division I will remain at 15 subs.
Divisions II and III will go to 18 subs.
According the rulebook, coaches start to get notified at 12 subs. For *all* levels.
I wonder if that's a typo. Seems to be a lot of notifications. Potentially the R2 could be notifying coaches 14 times (or more, if they are asked for the sub count before 12) per set.