OpenType® Specification Version 1.9.1

Core specification

• OpenType overview
• The OpenType font file
• Font file tables
• Advanced typographic extensions (OpenType layout)
• OpenType layout common table formats
• OpenType font variations overview
• OpenType font variations common table formats

Errata

• OpenType 1.9.1 errata

Appendices

• Recommendations
• OpenType Layout Tag Registry
• OpenType Design-Variation Axis Tag Registry
• TrueType outlines and instructions
  • TrueType fundamentals
  • Instructing TrueType Glyphs
  • The TrueType Instruction Set
  • Graphics State Summary
• OpenType Mirroring Pairs list
• Adobe technical note #5176: “The Compact Font Format Specification”
• Adobe technical note #5177: “Type 2 Charstring Format”
• Adobe Technical Note #5902: “PostScript Name Generation for Variation Fonts”
• Comparison of 'glyf', 'CFF ' and CFF2 tables
• Specification changes log file

OpenType 1.9.1 incorporates revisions in a preliminary working draft of the 5^th edition of the ISO/IEC 14496-22 “Open Font Format” standard. Current editions and amendments of ISO/IEC 14496-22 are freely available for download from the ISO website.

Updates to this specification are noted in the change log.