Windows Help redefines a number of Word for Windows features so that they have a different meaning in Help topic files than they do in a normal word-processing document. For example, Windows Help uses the footnote feature in Word for Windows to pass important topic information to the Help compiler. Topic footnotes have very specific meanings in Help, as described in the following table.
| Footnote | Name | Purpose |
| Asterisk (*) | Build tag | Defines a tag that specifies topics the compiler conditionally builds into the system. Build tags must be the first footnote in a topic when they are used. |
| At sign (@) | Comment | Includes an author-defined comment about the Help topic. |
| Dollar sign ($) | Title | Defines the title of a topic. |
| Exclamation Point (!) | Macro | Defines a macro that Help executes when the user enters the topic. |
| Letter K | Keyword | Defines a keyword the user uses to search for a topic. |
| Other letters | Multikey keyword | Defines an alternate keyword table that the user uses to search for a topic. |
| Plus sign (+) | Browse sequence | Defines a sequence that determines the order in which the user can browse through topics. |
| Pound sign (#) | Context string | Defines a context string that uniquely identifies a topic. Because hypertext relies on links provided by context strings, topics without context strings can only be accessed using keywords or browse sequences. |
Note:
If you are using build tags, footnote them at the very beginning of the topic. Place other footnotes in any order you want. For information about using each of these specific footnotes, see the following sections in this chapter.