preferred_name: GDP-alpha-D-rhamnose + N-acetyl-alpha-D-glucosaminyl-di-trans,octa-cis-undecaprenyl diphosphate => alpha-D-rhamnosyl-(1->3)-N-acetyl-alpha-D-glucosaminyl-1-diphospho-di-trans,octa-cis-undecaprenol + GDP + H(+)