From FDT Documentation
FDT's ASDoc view enables developers to easily read large pieces of documentation.
Showing ASDoc View
If your ASDoc View isn't already visible you can add it via Window>Show View>Other>FDT>ASDoc View.
You can also open the ASDoc view by clicking on the ASDoc icon at the bottom on the ASDoc popup.
Keyboard & Mouse
Still another way is to open it using your keyboard and mouse. The default keystroke to show the view is CTRL+SHIFT+F1.
Another powerful feature of the ASDoc view is being able to jump to the source file which the ASDoc View is referencing. This can be easily done by clicking on the 'open declaration' icon at the bottom of the ASDoc View.