The numbers in the lipid name are used to describe the fatty acid chains on the lipid. The numbers are generally presented in the format (number of carbons in fatty acid chain) : (number of double bonds in fatty acid chain), e.g., 16:0 would be 16 carbons in the fatty acid chain with zero double bonds, or the numeric representation of palmitic acid. Since glycerophospholipids contain two fatty acids per lipid, when only one number is given in the name it implies that both fatty acid are the same. The lipid 16:0 PC would be 16:0-16:0 PC, or dipalmitoyl PC. If there are two different fatty acids on the lipid, the name indicates both the fatty acid and the position. Therefore, 16:0-18:1 PC would represent 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine.