What does the phrase jus sanguinary refer to?

The phrase is actually pronounced "Jus Sanguinis". 
 
 It's a principle of nationality law by which citizenship is not determined by place of birth but by having one or both parents who are citizens of the state. Jus sanguinis is latin for 'right of blood' and is a social policy by which nationality or citizenship is determined not by place of birth, but by having an ancestor who is a national or citizen of the state. It contrasts with jus soli which is latin for 'right of soil'. Immigration and nationality act of 1952.

I hope this helps.