+line. If it returns @code{nil}, @code{adaptive-fill-regexp} gets
+a chance to find a prefix.
+
+@node Longlines
+@subsection Long Lines Mode
+@cindex refilling text, word processor style
+@cindex modes, Long Lines
+@cindex word wrap
+@cindex Long Lines minor mode
+
+ Long Lines mode is a minor mode for @dfn{word wrapping}; it lets you
+edit ``unfilled'' text files, which Emacs would normally display as a
+bunch of extremely long lines. Many text editors, such as those built
+into many web browsers, normally do word wrapping.
+
+@findex longlines-mode
+ To enable Long Lines mode, type @kbd{M-x longlines-mode}. If the
+text is full of long lines, this will ``wrap'' them
+immediately---i.e., break up to fit in the window. As you edit the
+text, Long Lines mode automatically re-wraps lines by inserting or
+deleting @dfn{soft newlines} as necessary (@pxref{Hard and Soft
+Newlines}.) These soft newlines won't show up when you save the
+buffer into a file, or when you copy the text into the kill ring,
+clipboard, or a register.
+
+@findex longlines-auto-wrap
+ Word wrapping is @emph{not} the same as ordinary filling
+(@pxref{Fill Commands}). It does not contract multiple spaces into a
+single space, recognize fill prefixes (@pxref{Fill Prefix}), or
+perform adaptive filling (@pxref{Adaptive Fill}). The reason for this
+is that a wrapped line is still, conceptually, a single line. Each
+soft newline is equivalent to exactly one space in that long line, and
+vice versa. However, you can still call filling functions such as
+@kbd{M-q}, and these will work as expected, inserting soft newlines
+that won't show up on disk or when the text is copied. You can even
+rely entirely on the normal fill commands by turning off automatic
+line wrapping, with @kbd{C-u M-x longlines-auto-wrap}. To turn
+automatic line wrapping back on, type @kbd{M-x longlines-auto-wrap}.
+
+@findex longlines-show-hard-newlines
+ Whenever you type @kbd{RET}, you are inserting a hard newline. If
+you want to see where all the hard newlines are, type @kbd{M-x
+longlines-show-hard-newlines}. This will mark each hard newline with
+a special symbol. The same command with a prefix argument turns this
+display off.
+
+ Long Lines mode does not change normal text files that are already
+filled, since the existing newlines are considered hard newlines.
+Before Long Lines can do anything, you need to transform each
+paragraph into a long line. One way is to set @code{fill-column} to a
+large number (e.g., @kbd{C-u 9999 C-x f}), re-fill all the paragraphs,
+and then set @code{fill-column} back to its original value.