Examples of symbols and conventions for drawing glycan structures. The monosaccharide symbol set from the Second Edition of Essentials of Glycobiology remains intact but has been extended to cover a wider range of monosaccharides found in nature. For reader convenience, a full table of symbols is reproduced on the inside cover of this book and is available as Online Appendix 1B, Table 1 at the NCBI Books website. A few examples of symbols and the use of this system to depict naturally occurring glycans are shown here. (Left) Branched “biantennary” N-glycan from a vertebrate, with two types of outer termini, depicted at different levels of structural details. (Right) Examples of glycosaminoglycan (GAG) chains from metazoan animals, a plant glycan, and a bacterial lipopolysaccharide.