ISO/IEC 9541-3:2012

Overview

ISO/IEC 9541-3:2012 - "Information technology - Font information interchange - Part 3: Glyph shape representation" defines the architecture and interchange formats for representing glyph shapes in font resources used across information processing systems. This second edition (2012) is a minor revision of the 1994 edition and updates the editorial syntax from SGML/DTD and ASN.1 to XML (DSDL / RELAX NG) for consistent, machine-parseable encoding.

The standard focuses on how glyph shapes are modeled and encoded so font resources can be reliably exchanged, validated, and reconstructed in document processing and electronic document interchange environments that recognize the RELAX NG parsing algorithm.

Key topics and technical requirements

• Glyph shape architecture: Specifies the structural approach to representing glyph outlines and shape components within a font-resource architecture.
• Interchange formats: Defines the formats used to serialize glyph shape information for interchange between systems.
• RELAX NG encoding: The encoding of glyph and font resource information is specified in RELAX NG (ISO/IEC 19757-2) representation to enable consistent generation and validation of font data.
• Compatibility with Parts 1 & 2: Works in conjunction with ISO/IEC 9541-1 and ISO/IEC 9541-2 which define the broader font resource architecture and font interchange formats.
• Editorial and revision history: Second edition consolidates earlier amendments (Amd.1:2005, Amd.2:2009) and migrates syntax to XML DSDL for modern toolchain compatibility.
• Intended processing environments: Emphasizes use where RELAX NG parsing is available, ensuring schema-driven validation and interoperability.

Applications and practical value

Who uses ISO/IEC 9541-3:2012:

• Font developers and foundries implementing interoperable font resource exports.
• Software engineers building font editors, rendering engines, or conversion tools that must exchange glyph data.
• Document processing and publishing systems that embed or reference fonts across platforms and workflows.
• Digital archivists and preservationists ensuring long-term, validated storage of font shape data.

Practical benefits:

• Interoperability - consistent glyph shape representation across tools and platforms.
• Validation and automation - RELAX NG schemas enable automated schema validation in toolchains.
• Standardized interchange - reduces errors when exchanging font resources in electronic document workflows.

Related standards

• ISO/IEC 9541-1 - Architecture of font resources
• ISO/IEC 9541-2 - Interchange formats for font resources
• ISO/IEC 19757-2 (RELAX NG) - Schema language used for encoding in this part

Keywords: ISO/IEC 9541-3, glyph shape representation, font interchange, RELAX NG, XML DSDL, font resources, font architecture, digital typography.