3.2.2 Defining Individual Topics

A topic starts with one or more \footnote statements and ends with a \page statement. All text and graphics specified between these statements belong to the topic.

Every topic must have a context string. Windows Help uses the context string to locate the topic when the user requests to view it. You assign a context string to a topic by using the \footnote statement and the number sign (#) footnote character. Context strings can consist of letters, digits, and the underscore character (_). To prevent conflicts, each context string in a help file must be unique.

You can also assign a title to the topic by using the \footnote statement and the dollar sign ($) footnote character. Windows Help uses the title to identify the topic in the History and Search dialog boxes. You must provide a title if you assign keywords to the topic.

The following example defines a small topic having the context string “topic1” and the title My Topic:

#{\footnote topic1}
${\footnote My Topic}
This is my first topic.
\par
\page

In general, you use the \par statement to mark the end of each paragraph. In this example, the \par statement marks the end of the only paragraph in the topic.

You can add a macro to a topic by using the \footnote statement and the exclamation point (!) as the footnote character. For example, the following \footnote statement adds the CopyTopic macro to the topic:

!{\footnote CopyTopic()}

Windows Help executes the macro each time it displays the topic.

The total size of text and graphics data stored in a topic must not exceed 64K. (Bitmaps included by using the bmc, bml, and bmr statements do not contribute to this total.)