In Java speek 'private' means only the class that declaired it can use it, 'public' means any one of any class can use it. Java also has the notion of 'protected' and 'package', basicly any subclass has access and any class in the same package has access respectivly.

The "SUBCLASSING" section would declair 'protected' (by convention only) methods. So it would not truely be 'public' in the sense of any class may call them, but it could be seen as 'public' in the sense that you have published their specs for all to see.