-an Emacs error.
-
- You don't have to be in the compilation buffer in order to use
-@code{next-error}. If one window on the selected frame can be the
-target of the @code{next-error} call, it is used. Else, if a buffer
-previously had @code{next-error} called on it, it is used. Else,
-if the current buffer can be the target of @code{next-error}, it is
-used. Else, all the buffers Emacs manages are tried for
-@code{next-error} support.
-
- @kbd{C-u C-x `} starts scanning from the beginning of the compilation
-buffer. This is one way to process the same set of errors again.
+an Emacs error. @w{@kbd{C-u C-x `}} starts scanning from the beginning of
+the compilation buffer, and goes to the first error's location.
+
+@vindex compilation-skip-threshold
+ By default, @w{@kbd{C-x `}} skips less important messages. The variable
+@code{compilation-skip-threshold} controls this. If its value is 2,
+@w{@kbd{C-x `}} skips anything less than error, 1 skips anything less
+than warning, and 0 doesn't skip any messages. The default is 1.
+
+ When the window has a left fringe, an arrow in the fringe points to
+the current message in the compilation buffer. The variable
+@code{compilation-context-lines} controls the number of lines of
+leading context to display before the current message. Going to an
+error message location scrolls the @samp{*compilation*} buffer to put
+the message that far down from the top. The value @code{nil} is
+special: if there's a left fringe, the window doesn't scroll at all
+if the message is already visible. If there is no left fringe,
+@code{nil} means display the message at the top of the window.
+
+ If you're not in the compilation buffer when you run
+@code{next-error}, Emacs will look for a buffer that contains error
+messages. First, it looks for one displayed in the selected frame,
+then for one that previously had @code{next-error} called on it, and
+then at the current buffer. Finally, Emacs looks at all the remaining
+buffers. @code{next-error} signals an error if it can't find any such
+buffer.