A position reference system (100) for multilateral exit construction in a wellbore (32). The system (100) includes a casing string (34) having a window joint (106) and a pair of latch couplings (102, 104) interconnected therein and positioned in the wellbore (32). The first latch coupling (102) has a first inner profile operably engagable with a mating profile of a first latch assembly (114) to anchor and orient the first latch assembly (114) relative to the window joint (106). The second latch coupling (104) has a second inner profile that is different from the first inner profile of the first latch coupling (102). The second inner profile is operably engagable with a mating profile of a second latch assembly (124) to anchor and orient the second latch assembly (124) relative to the window joint (106).