Apple Motion 3 - Manual (Page 505)

Chapter 6 Keyframes and Curves 505
You can also use the HUD and the Inspector to set and modify values for nearly every
option in the application. Any time you adjust a slider or other control, you have the
option of locking that change to the current frame, thereby setting a keyframe. From
that point on, no matter what else you do, that parameter always finds its way to that
specific value when playback reaches that frame.
You can also view and modify keyframes in the Timeline by clicking the Show/Hide
Keyframes button. Keyframes appear as small blue (or white, when selected) diamonds
beneath their parent object.
Selected keyframe Show/Hide Keyframes Button