@code{vertical}, sort the completions vertically in columns instead,
and if @code{one-column}, just use a single column.
+@vindex completions-sort
+ This user option controls how completions are sorted in the
+@samp{*Completions*} buffer. The default is @code{alphabetical}, but
+it can also be a function which will be called with the list of
+completions, and should return the list in the desired order.
+
@vindex completions-max-height
When @code{completions-max-height} is non-@code{nil}, it limits the
size of the completions window. It is specified in lines and include
automatically wrap around on reaching the beginning or the end of
the "*Completions*" buffer.
++++
*** New user option 'completions-sort'.
This option controls the sorting of the completion candidates in
the "*Completions*" buffer. Available styles are no sorting,