Chapter 8 on the IO APIs makes several references on page 434 and 439 to the String.format method, and points to Chapter 5 for further details. But I wasn't able to find these details...
Are the format method and formatting string syntax part of the exam ?
Good catch. Formatting details are not on the exam. You should know the format method exists on IO, but not the format.
In case you are wondering how such a "random" reference happened:
The details for formatting Strings are on the OCPJP 7, but not the OCPJP 8. In order to get to market so quickly, we started writing the book based on the Java 7 objectives and then went back and removed text for sections that weren't on the Java 8 exam. So we removed it from Chapter 5 (where it is out of scope) and missed removing the back reference.