Files that have CMSIS Configuration Wizard annotations can be opened with a graphical editor.
In the Project Explorer window, right-click on such files and use Open With → CMSIS Configuration Wizard.
Information about the selected Option is shown at the bottom of the window. Hover over an Option to view tooltip information.
The Source Editor tab switches to text mode.
Refer to the CMSIS documentation Configuration Wizard Annotations for information about source code annotations.