After creating individual topics by inserting page breaks, you then identify each topic by giving it a unique context string. Context strings identify each topic in the Help file. Each context string must be unique—it can be assigned to only one topic within the Help project.
Windows Help uses the context string to find a specific topic when users choose a hot spot that references that topic. Although not technically required, it is a good idea to assign a unique context-string identifier to all topics within the Help system. Topics without context strings cannot be accessed by hot spots (jumps, pop-ups, or macros), although they can be accessed through browse sequences or keyword searches. If writers include topics without context strings, it is their responsibility to ensure that users can access that information.
See the “Assigning Keywords” and “Specifying Browse Sequences” sections in this chapter for more information. Also, see Chapter 8, “Creating Links and Hot Spots,” for information about using context strings in hot spots.