Some doubt are casted about the credibility of corporate sustainability information. Using social and environmental ratings as proxy of social reputation and performance, several factors of disclosure are studied. Empirical results show that audits of social reports based on the GRI standard or the use of an integrated reporting do not always signal a higher level of social performance. But when companies use the GRI standard, they get higher social and environmental ratings. Those are even higher when companies are fully compliant with the GRI. Some parameters of the way companies communicate can then reveal and signal a higher social performance.