+ @kbd{C-u M-g M-g}, that is @code{goto-line} with a prefix argument
+of just @kbd{C-u}, reads a number @var{n} using the minibuffer,
+selects the most recently selected buffer other than the current
+buffer in another window, and then moves point to the beginning of
+line number @var{n} in that buffer. This is mainly useful in a buffer
+that refers to line numbers in another buffer: if point is on or just
+after a number, @code{goto-line} uses that number as the default for
+@var{n}. Note that prefix arguments other than just @kbd{C-u} behave
+differently. @kbd{C-u 4 M-g M-g} goes to line 4 in the @emph{current}
+buffer, without reading a number from the minibuffer. (Remember that
+@kbd{M-g M-g} without prefix argument reads a number @var{n} and then
+moves to line number @var{n} in the current buffer.)
+