While I have never read the text you are talking about, my guess is they are talking about Use Case Points.
Use Case Points are basically a way of guessing how large a project's goin to be and how much time/effort it will require. In a quick and dirty...
UCP (Use Case Points) = AW (Actor Weights) + UCW (Use Case Weights)
The Actor weights are determined by first getting the total number of actors, and then giving them a "weight" based on complexity:
* Simple (GUI) = 1
* Average (interactive interface) = 2
* Complex (API-level) = 3
Use Case Weights are determined in basically the same manner, with simple, average, complex weights (you determine the weights, but generally it's from the number of transactions/scenarios in the Use Case.
These are actually unadjusted weights, since you also need to compute based on where in the project cycle they need to be implemented (for example, will they be dealt with in dev,
test, security, etc). But you get the picture.
Again, you didn't include the actual text from Sun's book so I'm not sure this is what they're talking about, but that's what a Use Case Point is.