Plays a key role in the degradation of rhamnogalacturonan in the cell wall. Acts in synergy together with rhamnogalacturonase A (RGase A) and rhamnogalacturonase B (RGase B). Hydrolytic cleavage of 2-O-acetyl- or 3-O-acetyl groups of alpha-D-galacturonic acid in rhamnogalacturonan I. Optimum pH is 6.0. Carbohydrate at Asn-199 is composed of GlcNAc and Man. Belongs to the 'GDSL' lipolytic enzyme family.