===================================================================
RCS file: /cvs/mandoc/mandoc.1,v
retrieving revision 1.215
retrieving revision 1.219
diff -u -p -r1.215 -r1.219
--- mandoc/mandoc.1	2017/07/06 22:59:48	1.215
+++ mandoc/mandoc.1	2017/09/07 14:55:12	1.219
@@ -1,4 +1,4 @@
-.\"	$Id: mandoc.1,v 1.215 2017/07/06 22:59:48 schwarze Exp $
+.\"	$Id: mandoc.1,v 1.219 2017/09/07 14:55:12 schwarze Exp $
 .\"
 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 .\" Copyright (c) 2012, 2014-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: July 6 2017 $
+.Dd $Mdocdate: September 7 2017 $
 .Dt MANDOC 1
 .Os
 .Sh NAME
@@ -238,7 +238,9 @@ See
 .It Fl T Cm lint
 Parse only: produce no output.
 Implies
-.Fl W Cm all .
+.Fl W Cm all
+and redirects parser messages, which usually appear
+on standard error output, to standard output.
 .It Fl T Cm locale
 Encode output using the current locale.
 This is the default.
@@ -313,6 +315,20 @@ and seven for
 .Xr man 7 .
 Increasing this is not recommended; it may result in degraded formatting,
 for example overfull lines or ugly line breaks.
+.It Cm mdoc
+Format
+.Xr man 7
+input files in
+.Xr mdoc 7
+output style.
+Specifically, this suppresses the two additional blank lines near the
+top and the bottom of each page, and it implies
+.Fl O Cm indent Ns =5 .
+One useful application is for checking that
+.Fl T Cm man
+output formats in the same way as the
+.Xr mdoc 7
+source it was generated from.
 .It Cm width Ns = Ns Ar width
 The output width is set to
 .Ar width .
@@ -719,32 +735,13 @@ so using GNU troff instead of
 .Nm
 to process the file may be preferable.
 .It Cm error
-An input file contains invalid syntax that cannot be safely interpreted.
-By discarding part of the input or inserting missing tokens,
-the parser is able to continue, and the error does not prevent
-generation of formatted output, but typically, preparing that
-output involves information loss, broken document structure
-or unintended formatting, no matter whether
-.Nm
-or GNU troff is used.
-In many cases, the output of
-.Nm
-and GNU troff is identical, but in some,
-.Nm
-is more resilient than GNU troff with respect to malformed input.
-.Pp
-Non-existent or unreadable input files are also reported on the
-.Cm error
-level.
-In that case, the parser cannot even be started and no output
-is produced from those input files.
+Indicates a risk of information loss or severe misformatting,
+in most cases caused by serious syntax errors.
 .It Cm warning
-An input file uses obsolete, discouraged or non-portable syntax.
-All the same, the meaning of the input is unambiguous and a correct
-rendering can be produced.
-Documents causing warnings may render poorly when using other
-formatting tools instead of
-.Nm .
+Indicates a risk that the information shown or its formatting
+may mismatch the author's intent in minor ways.
+Additionally, syntax errors are classified at least as warnings,
+even if they do not usually cause misformatting.
 .It Cm style
 An input file uses dubious or discouraged style.
 This is not a complaint about the syntax, and probably neither
@@ -758,7 +755,7 @@ Please use your good judgement to decide whether any p
 .Cm style
 suggestion really justifies a change to the input file.
 .It Cm base
-A convertion used in the base system of a specific operating system
+A convention used in the base system of a specific operating system
 is not adhered to.
 These are not markup mistakes, and neither the quality of formatting
 nor portability are in danger.