To designate subprojects to be merged, list the subproject paths and titles. For example:
[HelpMerge] ; Subproject name and path = Title of subproject ..\api\LibRef = API Library Reference
Each [HelpMerge] entry specifies a subproject base file name, including a relative path if the subproject is in a different directory, and the title to be displayed for that subproject in the main-project contents. The relative path must be correct at run time.
If your main-project DITA document includes links to DITA files that are part of a subproject listed in [HelpMerge], specify how those linked-to DITA files are mapped to their subprojects. For example:
[OHMergeFiles] ; Mapping of Frame files which are linked to by files in the current ; project, but are themselves part of another OH project that is ; listed in [HelpMerge], to the name of that project. ; Omit all file extensions. ; file path = subproject path (no prefix, no extension) D:/Library/AppxB=../api/LibRef
It is best to include a path, because you could have several files with the same name (such as Glossary) in several different books from which you generate different OmniHelp projects; without file paths, you would have no way to differentiate them.
To handle several possible paths to the same file, you can add a line for each path. For example:
[OHMergeFiles] ChapA=BookA ChapB=BookB .../GroupB/ChapB=BookB G:/test/GroupB/ChapB=BookB
Although you can use either forward slashes or backslashes in paths, forward slashes are preferred. DITA2Go uses those cross-reference paths to find the referenced files.