A new version of the OpenType spec — version 1.8.3 — has been published:
While the content navigation links for the current version now all point to 1.8.3 pages, the previous version has been retained. I also managed to get OT1.8.1 migrated to the new site. (Maybe more can be added over time.) See the new Archived versions page:
Here’s a brief summary of what’s changed in OpenType 1.8.3:
The most significant technical changes are to the SVG table: these were developed in a joint effort among Microsoft, Apple, Adobe, Google and others. The motivation for the changes was that the spec was too loosely defined, and SVG+CSS is too vast, so without more specific guidance there was no likelihood of obtaining interoperability. These changes make the spec much more specific as to what must/should/should not/must not be used in fonts and supported in apps.
A few other pages have significant but mostly editorial changes:
There are some minor technical corrections in various pages, most or all in response to review comments, bug reports or comments on the drafts for ISO/IEC 14996-22 4th edition.
After many years, the TrueType instruction content has finally been migrated from a Microsoft Word document and integrated with the rest of the spec! (Almost 20 years ago, that was said to be “in progress”.)
There are a bunch of purely editorial changes. As I worked on the spec over 1.8, 1.8.1 and 1.8.2, I often encountered editorial inconsistencies, and I was constantly having to decide, “How should that be expressed and presented?” For some of these that occur repeatedly throughout the spec, I’ve made changes over these past few releases to bring consistency. This has what I think will be the last major batch of that kind of change: applying previously-adopted conventions to some remaining pages (e.g., MATH), and adopting a convention for how tag values (tables, features, etc.) are cited.
Complete details are provided in the change log: