This document is Part 3 of ISO/IEC 19776, Extensible 3D (X3D) encodings, corresponding to ISO/IEC 19975-1 X3D Architecture version 4.0, using X3D Canonical Form with Fast Infoset (FI) compression. The full title of this part of the International Standard is: Information technology — Computer graphics, image processing and environmental data representation — Extensible (X3D) encodings — Part 3: Compressed binary encoding.

Background	Clauses	Annexes
Foreword	1 Scope	A Fast infoset tables
Introduction	2 Normative references	B Node compressor registry
	3  Terms, definitions and abbreviated terms           Definitions, acronyms, and abbreviations	C Examples
	4 Concepts	Bibliography
	5 Encoding of fields	Verify correct inclusion of Fast Infoset in this document. Reference proper usage of gzip, zip algorithms.
	6 Conformance	Consider discussion of glTF binary (.glb) capabilities and usage. 19776-4 will apply Efficient XML Interchange (EXI) with XML Security.

The Foreword provides background on the standards process for X3D encodings. The Introduction describes the purpose, design criteria, and characteristics of X3D encodings. The following clauses define this part of ISO/IEC 19776:

1. Scope defines the problem area that the Compressed binary encoding of X3D addresses.
2. Normative references lists the normative standards referenced in this part of ISO/IEC 19776.
3. Terms, definitions and abbreviated terms Definitions contains the glossary of terminology used in this part of ISO/IEC 19776.
4. Concepts describes various fundamentals of the Compressed binary encoding of X3D.
5. Encoding of fields specifies the Compressed binary encoding of data types used by X3D nodes.
6. Conformance describes the conformance requirements for implementations of the Compressed binary encoding.

The following annexes are included in the specification:
There are several annexes included in the specification:

1. Fast infoset tables specifies the initial table values for each syntactic element.
2. Node compressor registry contains the listing of all registered node compressors.
3. Examples includes a variety of examples encoded in the X3D Compressed binary encoding.

Bibliography lists references providing additional which may have more information.