In a run-time merged CHM help system, it should be ok to have topics in the individual children with the same name.
I am migrating an inherited help system where this is the case e.g. multiple 01_Title.htm in the various children.
I have set up a new master TOC to aggregate the children and listed all the CHM in the [MERGE FILES] section.
In the children, I have listed all their siblings in the [MERGE FILES] section and specified that the master TOC is displayed when they are opened.
The wrong title is sometimes highlighted in the master TOC when a child is opened. Is there a solution apart from renaming the child topics?