Floating Contextual Toolbar
Oxygen XML Web Author includes a dynamic feature where certain editing contexts will trigger a floating toolbar with common actions that are available in the current editing context. For example, the actions available on the floating toolbar for DITA documents are listed at: DITA Floating Toolbar Actions.
The floating contextual toolbar is automatically displayed in various situations. For example, it appears when you select content inside a paragraph, table cell, list item, and more.
Controlling the context where a floating contextual toolbar will appear and the types of controls it will contain is done using CSS. You can find more details about this in the customization guide.