DITA2Go produces CSH alias entries from every TopicAlias PI marker in your DITA document whose content starts with one of the prefixes you specify. If you do not specify any prefixes, all TopicAlias PI markers become aliases.
To specify one or more alias prefixes for CSH calls to OmniHelp topics:
[OmniHelpOptions]
; AliasPrefix = all prefixes wanted in alias file, comma or space
; delimited; if omitted, all newlinks are included
; NOTE: wildcards do not work in prefixes
AliasPrefix = prefix1, prefix2, ...
[OmniHelpOptions]
AliasPrefix = HIDC_, IDH_
With this setting, the alias file would include the content of every TopicAlias PI marker in your document whose text starts with HIDC_ or IDH_.
DITA2Go always creates the alias file, needed even if empty.