Toggle to turn on/off active dataset indicator in legend. When it’s on, a red frame will show on legend of active dataset. By default when opening analysis tools from graph window, active data will be used as the input.

Click on other symbol in legend will change active dataset. The frame will show around the newly clicked plot symbol in legend.

In the past, user would have to choose Format: Page… to open Plot Details dialog. Check it on Legend/Titles tab.