The one-letter code system proposed here is a simple method to accurately describe structurally diverse oligosaccharides derived from heteroxylans. Substitutions or `molecular decoration(s)' of main-chain D-xylosyl moieties are designated by unique letters. Hence, an oligosaccharide is described by a series of single letters, beginning with the non- reducing D-xylosyl unit. Superscripted numbers are used to indicate the linkage position(s) of main-chain substitution(s) and, where necessary, superscripted lowercase letter(s) indicate the nature of non- glycosidic groups (e. g., methyl, acetyl, or phenolic derivative moieties) that can be present on the substituents. Although relatively simple and practical to use, this abbreviated system lends itself to the naming of a large number of different combinations of structural building blocks and substituents. In its present state, this system is, therefore, adequate to name and differentiate all currently known complex oligosaccharides derived from heteroxylans and is sufficiently flexible to accommodate new structures as they become available.