here is the difference of 1-308
The majority of people assume an autograph is the same as a signature. There are some very important differences. A legal signature is a agreement that you sign that can be use as evidence. An autograph on the other hand, is more or less a signed name as not legal document.
§ 1-308. Performance or Acceptance Under Reservation of Rights. (a) A party that with explicit reservation of rights performs or promises performance or assents to performance in a manner demanded or offered by the other party does not thereby prejudice the rights reserved.
admiralty court are performance court. You have to perform by there rule or you may get punished. If you signed a document under 1-308 you are not held to be liable outcome of a decision because you were force to sign something in order to perform and you did not completely volunteered to do so.