Board Thread:Wiki Discussions/@comment-1512913-20140521221412/@comment-1512913-20140521232444

The Rinnegan can also use some Sharingan-specific powers/techniques, like Sasuke's by Rinnegan-granted Infinite Tsukuyomi immunity Susanoo etc. not to mention Madara's Infinite Tsukuyomi reflects as Rinnegan in the eyes of the affected, despite IT being a Sharingan technique. But it's clearly used with his third Rinnegan, hence using power of the Sharingan with Rinnegan isn't that much of a secret code.