A person who receives formal lineage becomes a "disciple" of the master, literally ru men di tse, or "one who is permitted through the 'inner door,'" through formal Confucian ceremony makes public oaths to assume more deep, personal responsibility to the master and art. After formal acceptance as a disciple, the new initiate begins to be introduced to closely held secrets of the art. By tradition, every true master has deeper knowledge of the art that are passed to only a few initiated disciples. Most intriguing is the transmission of lineage. Although the term is often misused and misrepresented, true lineage is passed to the student through formal Confucian ceremony. True lineage is transferred when there was no gap and documented lineage has passed through from generation to generation via induction during formal ceremony. Although there is no test for lineage, since it is generally thought of as representing access to special knowledge as well as responsibility to the art, over time--at least within many groups--the teacher is assumed to have been extremely careful when accepting a disciple.
It is also important to bring up the matter that some teachers prefer to neither use, nor issue no rank whatsoever. They practice and get better and for them this is enough. I hold the deepest appreciation for some of my teacher who, at least when I studied with him, was not concerned with formal ranking. In the end, if quality is important, that is what the aspiring student will be concerned with. Formal ranking and lineage may, or may not show up, but that doesn't really matter. What matters is the degree of depth and dedication to the art, and the joy this brings to embrace a rare and beautiful thing.