Migrating to WinHelp 4.0 for Windows ’95 
WinHelp 4 is the help environment for Microsoft’s Windows 95 and Windows NT operating systems. Among the important new features of WinHelp 4 are more capable secondary windows, shortcut buttons, the ability to integrate multiple help files, What’s This? help, and better support for online coaches. Help authors must understand both the construction and the design aspects of these new features. They must also deal with the complexities of the transition from Windows 3.1 help to WinHelp 4.
Farkas, David K. and Joe Welinske. STC Proceedings (1996). Articles>Documentation>Online>Help