The tree form of I/O registers can be edited by classifying each register by a given category (folder).

Move the caret to an I/O register name you want to create and then click the toolbar button and enter a new category name directly from the keyboard.

Select a category name you want to edit and then click on it again and edit the category name directly from the keyboard.

Select a category you want to remove and then click the toolbar button However, only blank categories can be removed.

Drag-and-drop an I/O register name into any category. That way, the I/O registers are classified by a category.

Also, the order in which categories and I/O register names are displayed (one above or below another) can be freely changed by a drag-and-drop operation.