Although my mock exam web site contains a mock exam set that is organized based on the chapters of Khalid's book, I have never actually seen his book. Instead, my primary source of information for my mock exams was the Java Language Specification, so I can direct you to the chapter of the JLS that covers constructors.
The term "constructor header" appears to be something that Khalid defined to simplify the topic, so I can't offer any more information on that term beyond what appears in his book. All I can say is that a constructor declaration can include a "throws clause".
Dan Chisholm<br />SCJP 1.4<br /> <br /><a href="http://www.danchisholm.net/" target="_blank" rel="nofollow">Try my mock exam.</a>