Cognomen 博士 (Hakasi 
, 博士 
, Bakx 
) , in the entire world, is quite a rare surname. The cognomen 博士 is habitual in Netherlands, where it is quite a rare surname, Belgium, and Lithuania, where it is a rare surname. Not in comparison with a country's population, it most frequently occurs in Netherlands, China, and Belgium. Also, 博士 is the forename as well as the last name.