- When a window is less than the full width, text lines too long to
-fit are frequent. Continuing all those lines might be confusing, so
-if the variable @code{truncate-partial-width-windows} is
-non-@code{nil}, that forces truncation in all windows less than the
-full width of the screen, independent of the buffer being displayed
-and its value for @code{truncate-lines}. @xref{Line Truncation}.
+ When a window occupies less than the full width of the frame, it may
+become too narrow for most of the text lines in its buffer. If most of
+its lines are continued (@pxref{Continuation Lines}), the buffer may
+become difficult to read. Therefore, Emacs automatically truncates
+lines if the window width becomes narrower than 50 columns. This
+truncation occurs regardless of the value of the variable
+@code{truncate-lines} (@pxref{Line Truncation}); it is instead
+controlled by the variable @code{truncate-partial-width-windows}. If
+the value of @code{truncate-partial-width-windows} is a positive integer
+(the default is 50), that specifies the minimum width for a
+partial-width window before automatic line truncation occurs; if the
+value is @code{nil}, automatic line truncation is disabled; and for any
+other non-@code{nil} value, Emacs truncates lines in every partial-width
+window regardless of its width.