The Yates interoffice memo issued May, 2005 define what is "same or similar occupational". However, there is no guidance in this condition: one guy change job to a position that require only bachelor's degree and less than 5 years. His I-140 is EB2 catagory. Is there any restriction to apply AC21 portability in this job change? If there isn't any document to say no for this scenario, does that mean this job change is ok ?