International preliminary Examination is an optional part on the applicant for an International application, but all PCT applications nevertheless undergo examination either with or without having examiner interaction with the applicant. The Examiner - applicant interaction occurs only when a Demand is filed under Chapter II of the PCT. Filing of Demand is completely optional. A Demand is usually filed in response to the written opinion of the ISA (International Search Authority), especially if it is a negative opinion. Thus…