Open Scripting Architecture Reference Lots of documents, like this one, refer to the "Open Scripting Architecture Reference," which sounds useful to me. But I can't find it anywhere. Googling the title gets lots of non-authoritative links where people have posted old PDFs of what presumably is an earlier version of the same thing.

Where is it?
Have a look at https://applescriptlibrary.wordpress.com or use the search engine of your choice. The exact document you ask is here:


https://applescriptlibrary.files.wordpress.com/2013/11/open-scripting-architecture.pdf


It's listed as legacy and from 2007. See my comment above about carbon API such as this being deprecated when 10.8 Mountain Lion was released. It might be better to just use the current guide you linked above unless you have specific needs to do research or support older OS and tools.