The project configuration file that DITA2Go Project Manager copied to your output directory when you set up your conversion project already contains the correct setting for the output type (which is indicated by the configuration file name). Do not change this setting.
Table 4-1 shows the name of the project configuration file for each output type, and the preset extension for output files. You can change the setting for the output file extension, for all output types except WinHelp.
For example, to specify a different file extension for HTML output:
[Setup]
; FileSuffix = suffix used for output file extension and in
; cross references
FileSuffix = .html
The leading dot on the extension is optional.