One story about the gadlus of Reb Aryeh Levin. He was once asked to sign on a certain kol korei. He did not want to. (I believe because his way was to gently teach through love and example, not by loud declarations.) But he did not want to offend those who asked him, either. So he said, look, these signers are all great Rabbonim and Gedolei Torah. But I am a plain Jew and they call me simply, Aryeh. It would not be proper for a simple Aryeh with no title to sign the same document as all these choshuveh Rabbonim.