bug#51210: Customizable other-window-for-scrolling

[Juri Linkov]

>> 'beginning-of-buffer-other-window' has such line at the end:
>> 
>>   (recenter '(t))
>> 
>> Clearly it makes no sense to recenter at the beginning of the buffer.
>> So the value '(t)' was intended only to refresh the screen?
>> Then the same line in 'end-of-buffer-other-window'
>> should only refresh the screen, not recenter.
>
> I'm not sure I understand how all of this is relevant.  Please
> elaborate.

Currently the implementation of beginning-of-buffer-other-window
is this:

(defun beginning-of-buffer-other-window (arg)
  (with-selected-window (other-window-for-scrolling)
    ;; Set point and mark in that window's buffer.
    (with-no-warnings
      (beginning-of-buffer arg))
    ;; Set point accordingly.
    (recenter '(t))))

It's not clear what does the last comment mean.
'recenter' should set point accordingly to what?
And what does (recenter '(t)) do at the beginning of the buffer?