Nikon NIKKOR Z 800mm f/6.3 VR S Lens - Manual (Page 29)

Using Stored Focus Positions (Memory Recall)
The saved focus position will be restored while the control to which [Recall focus
position] has been assigned via [Custom controls] or [Custom controls
(shooting)] is pressed. Release the control to resume normal auto or manual
focus.
Pressing the Shutter-Release Button Halfway During
Memory Recall
The camera will not refocus if the shutter-release button is pressed halfway while
the control is pressed, regardless of the focus mode selected.
Memory Recall
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