Currently it is possible to call:

com.sun.tdk.litesig.SignatureTest -FileName api.sig -NotPresent forbidded.lst

but it is impossible to call:

com.sun.tdk.litesig.SignatureTest -NotPresent forbidded.lst

Meanwhile second variant is necessary for Bluray CTS.

In other words sigtest shall allow just to check that some classes are absent without specifying any signature file.