Deleting topics and occurrences
You can delete an individual topic or the group of topics under the one selected. A group in Topicscape is the strict hierarchy of topics under a selected topic. This means the children, grandchildren, and so on of the topic, until, down each branch, an end is reached (topic and descendents).
The simplest way to delete is to select the topic and press the Delete key (delete just that topic) or Shift+Delete (delete the group of topics of which the selected one is the topmost).
If you delete just the selected topic, but it has children, the children may become isolated. Topicscape generally joins isolated topics to a special topic called Topicscape Islands that appears when needed on the left of the 3D 'Scape or 2D Map. On slower PCs checking for isolation of topics can be turned off for speed. Most PCs nowadays do not need this option.
In the 3D view, deleted topics that are visible in the Map or 'Scape, will be shown in black until the view is refreshed (change Current Topic or press F5). Topics in the group to be deleted but that are shared with another group are protected from deletion. These will be shown as semi-transparent. You can stop the balck or transparent cones from appearing in the Tools | Options panel. There is a tab "User Preferences" which has a checkbox "Do not show black cones when deleting topics".
Keep in mind that more than one instance a topic can appear in the Map or 'Scape at a time. All instances of the just deleted topic will appear as black in such a case.
You cannot delete the Current Topic. To delete a topic that happens to be 'current' at the time, make another one into the Current Topic first. You can't delete the 'Home topic' either. This is the first topic you make when you start a new Topicscape. If you right-click on either the Current Topic or the Home topic, you will see the deletion menu items grayed out (disabled).
Other ways of deleting topics
1. Drag (the green dot) to the 'Out Tray' drop down: "Delete".
Please refer to Move or delete topics and occurrences through the Out Tray.
2. Use the right-click pop-up menu or the Edit menu in the main menu bar.
Chose the type of deletion you want: "Delete this topic only..." or "Delete this topic & descendants...".
The deletion report
When you start to delete a topic or a group of topics, you will see a report showing the full effect of that deletion. You can elect to suppress all such future reports using the "don't show this again" checkbox.
Set the reports to appear again using the Tools | Options panel | User Preferences | Show deletion reports checkbox.
In Topicscape it is sometimes useful to connect topics in a chain that eventually leads back to the original topic. As the Current Topic at any one time cannot be deleted, a chain of topics that includes the Current Topic will be protected too. You'll have to make a topic outside the group current first.
The above refers to deleting topics--their occurrences are included in the deletion process. Inside a Topic Center you can select occurrences and delete them using the Delete key, the pop-up menu, the main menu bar or by dragging them to the Out Tray, then down to the Delete box.