Five-value rich lines‎, ‎Borel directions and uniqueness of meromorphic functions

For a meromorphic function f in the complex plane, we shall introduce the definition of fivevalue rich line of f, and study the uniqueness of meromorphic functions of finite order in an angular domain by involving the five-value rich line and Borel directions. Finally, the relationship between a five-value rich line and a Borel direction is discussed, that is, every Borel direction of f is its five-value rich line, and the inverse statement holds when f is of infinite order.