The structure of this document is as follows. Clauses 2-4 specify the terms, abbreviations, symbols and conventions used throughout the document. Clauses 5-11 contain definitions of the description tools standardized by 15938-3 grouped by the visual
features they are associated with, starting with basic structures and containers in Clause 5, through color, texture, shape, motion, localization in Clause 10. Clause 11 contains the remaining, unclassified items.

Each description tool is described by the following subclauses:

• Syntax: Normative DDL specification of the Ds or DSs.

• Binary Syntax: Normative binary representation of the Ds or DSs.

• Semantic: Normative definition of the semantics of all the components of the corresponding D or DS.