WRI has changed the way style sheets work in Version 10 and does not appear to give any information on this. It looks like Subtitle, and perhaps Subsubtitle are somehow grouped with Title but there is no way to get at them. They are not on any of the Style menus.
They have also introduced a new Chapter Cell in the Default sheet that usurps the key number for Subtitle - so I can't get at it that way either.
Does anyone know how to enter these old standby Cell styles?
It is one thing to improve functionality of existing Cell Styles but an entirely other thing to change their basic underlying format and accessibility.
Another problem in V10 is that the various negative spaces, e.g., [NegativeVeryThinSpace]", no longer work as they used to. They now insert large negative spaces so one can no longer fine tune formats with them. One either gets a large gap or overlap.