Hi,
I just got my work permit approved through the intra-company transfer provision to move to my company's subsidiary firm based in Canada from Italy. We have our factory based in Italy only so I guess the specialized knowledge criteria was met due to a valid experience of 2 years with the HQ and factory office.
I had presented just my experience certificate and pay slips during the time period as proof of my expertise in addition to the letter and job offer details from new employer.
I guess if the position you have applied for could be filled in by a Canadian citizen or a resident, then intra-company transfer may not work out and you may have to apply for one of the other provisions for a proper work visa involving Labour Market Impact Assesment (LMIA)