Shemiras Halashon Halachos
Hilchos Rechilus, chapter 8, section 4 Dust of rechilus also includes telling Reuven that Shimon said of him something that is not derogatory, but something that people generally don't like to be said of them.
Hilchos Rechilus, chapter 8, section 5 A person must conceal information told to him confidentially even if revealing the secret involves no rechilus. Because revealing the secret causes the person and can damage his plans. It is always not modest to reveal secrets and is contrary to what the person wanted.