-This function creates a new window adjacent to @var{window}. It returns
-the new window which is always a live window. The argument @var{window}
-can denote any window and defaults to the selected one. This function
-does not change the selected window.
-
-Optional second argument @var{size} a positive number means make
-@var{window} @var{size} lines (or columns) tall. If @var{size} is
-negative, make the new window @minus{}@var{size} lines (or columns)
-tall. If @var{size} is omitted or @code{nil}, then @var{window} is
-divided evenly into two parts. (If there is an odd line, it is
-allocated to the new window.)
-
-If splitting would result in making a window smaller than
-@code{window-min-height} or @code{window-min-width} (@pxref{Window
-Sizes}), this function usually signals an error. However, if @var{size}
-is non-@code{nil} and valid, a new window of the requested size is
-created. (A size value would be invalid if it assigned less than one
-line or less than two columns to the new window.)
-
-Optional third argument @var{side} @code{nil} (or @code{below})
-specifies that the new window shall be located below @var{window}. The
-value @code{above} means the new window will be located above
-@var{window}. In both cases @var{size} specifies the new number of
-lines for @var{window} (or the new window if @var{size} is negative)
-including space reserved for the mode and/or header line.
-
-If @var{side} is @code{t} or @code{right} the new window will be
-positioned on the right side of @var{window}. The value @code{left}
-means the new window will be located on the left side of @var{window}.
-In both cases @var{size} specifies the new number of columns for
-@var{window} (or the new window provided @var{size} is negative)
-including space reserved for margins, fringes and the scroll bar or a
-divider column.
-
-Any other non-@code{nil} value for @var{side} is currently handled like
-@code{t} (or @code{right}). Since this might change in the future,
-application programs should refrain from using other values.
-
-If @var{window} is live, properties of the new window like margins and
-scroll bars are inherited from @var{window}. If @var{window} is an
-internal window, these properties, as well as the buffer shown in the
-new window, are inherited from the window selected on @var{window}'s
-frame.
-
-If @code{ignore-window-parameters} is non-@code{nil}, this function
-ignores window parameters (@pxref{Window Parameters}). Otherwise, if
-the @code{split-window} parameter of @var{window} is @code{t}, it splits
-the window disregarding any other window parameters. If the
-@code{split-window} parameter specifies a function, that function is
-called with the arguments @var{window}, @var{size}, and @var{side} to
-split @var{window}. If that function is @code{ignore}, nothing is done.
+This function creates a new live window next to the window
+@var{window}. If @var{window} is omitted or @code{nil}, it defaults
+to the selected window. That window is ``split'', and reduced in
+size. The space is taken up by the new window, which is returned.
+
+The optional second argument @var{size} determines the sizes of the
+@var{window} and/or the new window. If it is omitted or @code{nil},
+both windows are given equal sizes; if there is an odd line, it is
+allocated to the new window. If @var{size} is a positive number,
+@var{window} is given @var{size} lines (or columns, depending on the
+value of @var{side}). If @var{size} is a negative number, the new
+window is given @minus{}@var{size} lines (or columns).
+
+If @var{size} is @code{nil}, this function obeys the variables
+@code{window-min-height} and @code{window-min-width}. @xref{Change
+Window,,Deleting and Rearranging Windows, emacs, The GNU Emacs
+Manual}. Thus, it signals an error if splitting would result in
+making a window smaller than those variables specify. However, a
+non-@code{nil} value for @var{size} causes those variables to be
+ignored; in that case, the smallest allowable window is considered to
+be one that has space for a text area one line tall and/or two columns
+wide.
+
+The optional third argument @var{side} determines the position of the
+new window relative to @var{window}. If it is @code{nil} or
+@code{below}, the new window is placed below @var{window}. If it is
+@code{above}, the new window is placed above @var{window}. In both
+these cases, @var{size} specifies a total window height, in lines.
+
+If @var{side} is @code{t} or @code{right}, the new window is placed on
+the right of @var{window}. If @var{side} is @code{left}, the new
+window is placed on the left of @var{window}. In both these cases,
+@var{size} specifies a total window width, in columns.
+
+If @var{window} is a live window, the new window inherits various
+properties from it, including margins and scroll bars. If
+@var{window} is an internal window, the new window inherits the
+properties of the window selected within @var{window}'s frame.
+
+If the variable @code{ignore-window-parameters} is non-@code{nil}
+(@pxref{Window Parameters}), this function ignores window parameters.
+Otherwise, it consults the @code{split-window} parameter of
+@var{window}; if this is @code{t}, it splits the window disregarding
+any other window parameters. If the @code{split-window} parameter
+specifies a function, that function is called with the arguments
+@var{window}, @var{size}, and @var{side} to split @var{window}, in
+lieu of the usual action of @code{split-window}.