Click the video below to play it. To view in fullscreen mode, first click the YouTube link at the bottom of the video to launch the video on the YouTube site. Then, click the fullscreen button (rightmost button at bottom of video).
Recorded in 1280 X 720 resolution.
At 8:30 he starts discussing delta station (and delta offset, which is similar): when setting the origin, the first click establishes the alignment for stationing and the second click sets where dS=0.
(I love his guy's voice. He needs to do all the videos.)