Help+Manual can archive every previous version of every topic whenever you save your help project. It can be an alternative to version control systems for individual help authors. It allows you to compare multiple versions of a topic and refer to or revert to a previous version if you find that you or another author has made changes that you want to undo.
Topic history needs to be activated in each project where you want to use it. You can activate this option in Configuration > Common Properties > Miscellaneous.
IMPORTANT: You cannot use topic history if you are using version control
Note that you cannot activate topic history in projects linked to version control systems. This is also not necessary, because then the entire history of your project is stored in the version control system.
To view and compare previous versions of the current topic select Show History in the topic menu in the top left corner of the topic editor window:
When you display the history you see the previous versions on the right. You can select which version you want to view with the menu above the history display on the left. You can revert the current topic to the displayed history version with the option on the right.