Macintosh OS 8 Human Interface Guidelines
http://developer.apple.com/techpubs/mac/HIGOS8Guide/thig-2.html

Apple Inc.
1997

Abstract:

This document describes the additions and changes to Macintosh Human Interface Guidelines related to the release of Mac OS 8. Specifically, it presents guidelines for taking advantage of the Mac OS platinum appearance and the Appearance Manager. This document does not replace Macintosh Human Interface Guidelines.