Clicking on the question mark symbol in the main menu bar and in pop-up windows opens the online help for portatour® in a separate browser tab.
The help is context sensitive, i.e. the displayed help content refers exactly to the program page you are currently using. Sometimes you will see links on the bottom of the help page which allow you to switch to subchapters and more detailed information. Click on Help Center in the left upper corner to go to the start.
Enable the opening in case the online help is blocked by your browser's pop-up blocker.