### 9.11.2 Determining whether you need map and alias files

Whether you need map and alias files depends on the following:

• the type of API call the developers use in the application program

• the type of CSH destination you use in your document.

Table 9-3 summarizes the most likely circumstances.

Table 9-3 Map and alias files needed for CSH in HTML Help

CSH destination type | Application call type | Link type | Files needed
Marker | HH_HELP_CONTEXT | Numeric ID | Map and alias
Special paragraph | HH_DISPLAY_TOPIC | .htm file name | Neither

Markers

If you use markers for CSH destinations, you need both a map file and an alias file:

map file | Associates each numeric ID in the application with a symbolic ID in your document, where the symbolic ID is the relevant marker text.
alias file | Associates each symbolic ID in your document with the .htm file where the relevant marker is located.

When you use markers, developers should use the HH_HELP_CONTEXT API, and specify topics by numeric ID. You need the map and alias files to associate their numeric IDs with your symbolic IDs. Each time you convert your FrameMaker document to HTML Help, Mif2Go uses the symbolic IDs to generate an alias file; see §9.11.4 Creating an alias file for CSH links. Usually the developers provide the map file.

When developers use the HH_HELP_CONTEXT API, the application must send a numeric ID, and you must have the map file in your project to interpret the numeric ID. The developers need only the map file. You need only to add to your HTML Help project file the name of the map file and the name of the alias file, before compiling. You can do this via configuration setting; see §9.11.3 Specifying a map file for CSH links.

Special paragraphs

If you use special paragraphs for CSH destinations, developers should use the HH_DISPLAY_TOPIC API, and specify topics by file name. You do not need an alias file or a map file. Calls from the application program reference the file names you put in the special paragraphs directly, via the compiled help file; check HTML Help Workshop for the correct syntax.

| 9.11.1.2 Using special paragraphs for CSH destinations |  | 9.11.3 Specifying a map file for CSH links |