Korea
Sunim is the Korean title for a Buddhist monk or Buddhist nun of any tradition, and does not denote any specific rank or qualification. It is considered respectful to refer to senior monks or nuns in Korea as Kun sunim, and this polite way of expressing the title can also denote some sort of realization on the part of the individual being addressed. In most Korean temples, a middle-aged monk assumes the role of a juji sunim, who serves administrative functions. The eldest sunim is typically seen as a symbolic leader of the younger sunims.
In Korean Soen, Inka (In'ga) typically refers to the private acknowledgement of dharma transmission from a teacher to their student. "Transmission" is used to refer to the public ceremonial version of the same acknowledgement. Both are considered equal in authority and "realization". A monk with either In'ga or the public "transmission" is qualified to hold the post of Soen Sa, or "Zen Master" for a temple, and give transmission to their own students (either, In'ga or public "transmission"). The majority of Zen Masters in Korea have only received, and only give In'ga, with the formal transmission ceremony being far more rare.
In the Kwan Um School of Zen, founded by Korean Zen teacher Seung Sahn in America and Europe, a Zen master can be referred to as a Soen Sa Nim ("Soen" or "Son" being Korean for Chan, or Zen) — although this term usually is used only in reference to Seung Sahn himself (usually with the honorific "Dae", meaning "great" - as in "Dae Soen Sa Nim").
Read more about this topic: Zen Master