Nuclear power plants may use commercial grade items if they can pass special tests or inspections, which is called Commercial Grade Item Dedication (CGID). Digital items, however, should follow EPRI TR-106439 to be applied to nuclear power plants. This paper explains the scheme and requirements of the EPRI TR-106439 and introduces some guidelines. Firstly, in order to clarify requirements of the EPRI TR-106439, code interpretation is performed. And through case study of digital indicator, limitations of EPRI TR-106439 are mentioned, and improvement direction is proposed.