The following is the list of problems with apiCover 1.3 UG:

What are invokevirtual or invokeinterface instruction? (page 3)
thomas.rivelli added "Java virtual machine" as Kevin suggested.
java com.sun.tdk.apicover.Main command line needs -cp Classpaht (page 7)
thomas.rivelli agree with Kevin, the Xref covers this.
TABLE 3-3 ML should HTML (page 10)
fixed by thomas.rivelli
Example Genreate the sampleapi.sig does not work (page 12)
Command line for generated sigtest does not match the one in the setup shell script (page 13)
Output of generated sigtest file is wrong (page 13)