The OpenType™ specification has been formatted in HTML, but may link to .PDF files.

OpenType specification version 1.8

• 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 1.8 Errata

Appendices

• Recommendations
• OpenType Layout Tag Registry
• The WGL4.0 character set
• TrueType fundamentals
• The TrueType instruction set
• OpenType Mirroring Pairs List
• Adobe technical note #5176: “The Compact Font Format Specification.”
• Adobe technical note #5177: “Type 2 Charstring Format.”
• The CFF 2 Charstring Format
• Adobe Technical Note #5902: “PostScript Name Generation for Variation Fonts”
• Specification changes log file

OpenType 1.8 incorporates revisions in Amendment 1 and Draft Amendment 2 of the ISO/IEC 14496-22:2015 “Open Font Format (3rd edition)” standard. Additionally, it incorporates extensions not included in ISO/IEC 14496-22:2015 plus Amendments 1 and 2: the 'MERG', 'meta' and 'sbix' tables, and all of the addtions related to OpenType Font Variations. Current editions and amendments of ISO/IEC 14496-22 are freely available for download from theISO website.

Updates to this specification are noted in the change log.