It's just one example of many. The title of this thread is " Photoshop reference manual? ", and its purpose it to find out how to efficiently find documentation on Adobe Photoshop features when I'm in the middle of trying to get work done.
yes, the reference documents were comprehensive. Unfortunately the only extant (remnant) PDF for Photoshop is CS6. Current CC version is ONLY online, now. One of the better publishers of books about Adobe's apps--and recommended by Adobe--is Wiley Publishing, which became famous for their "Dummies" series about software.
(Portable Document Format) PDF supports and preserves all of Photoshop’s features, including the ability to use spot colors, something the EPS format does not support. PDF gives you the choice of either JPEG compression, complete with a Quality setting to balance image quality with file size, or lossless ZIP compression.
The Preferences object is a property of the Application object. In the Adobe Photoshop JavaScript Scripting Reference, or in the ExtendScript Object Model Viewer, look up the Preferences object to view all of the settings properties you can use. Additionally, look up the preferences property on the Application object.