Split tagging into a validation part including prioritization

in tag.{h,c} and {mdoc,man}_validate.c
and into a formatting part including command line argument checking
in term_tag.{h,c}, html.c, and {mdoc|man}_{term|html}.c.

Immediate functional benefits include:
* Improved prioritization of automatic tags for .Em and .Sy.
* Avoiding bogus automatic tags when .Em, .Fn, or .Sy are explicitly tagged.
* Explicit tagging of .Er and .Fl now works in HTML output.
* Automatic tagging of .IP and .TP now works in HTML output.
But mainly, this patch provides clean earth to build further improvements on.

Technical changes:
* Main program: Write a tag file for ASCII and UTF-8 output only.
* All formatters: There is no more need to delay writing the tags.
* mdoc(7)+man(7) formatters: No more need for elaborate syntax tree inspection.
* HTML formatter: If available, use the "string" attribute as the tag.
* HTML formatter: New function to write permalinks, to reduce code duplication.

Style cleanup in the vicinity while here:
* mdoc(7) terminal formatter: To set up bold font for children,
defer to termp_bold_pre() rather than calling term_fontpush() manually.
* mdoc(7) terminal formatter: Garbage collect some duplicate functions.
* mdoc(7) HTML formatter: Unify <code> handling, delete redundant functions.
* Where possible, use switch statements rather than if cascades.
* Get rid of some more Yoda notation.

The necessity for such changes was first discussed with kn@, but i didn't
bother him with a request to review the resulting -673/+782 line patch.

102 files changed, 1334 insertions, 86 deletions

diff --git a/regress/copyless b/regress/copyless
new file mode 100755
index 00000000..a00c0009
--- /dev/null
+++ b/regress/copyless
@@ -0,0 +1,14 @@
+#!/bin/sh
+set -e
+umask 022
+if [ "$#" -ne 4 ]; then
+	echo "$0 $*: $# args instead of 4" 1>&2
+	exit 1
+fi
+if [ "$2" != "-T" ]; then
+	echo "$0 $*: second arg is not -T" 1>&2
+	exit 1
+fi
+cut -d ' ' -f 1,3 "$3" > "$1.mandoc_tag"
+cp "$4" "$1.mandoc_ascii"
+exit 0
diff --git a/regress/man/IP/Makefile b/regress/man/IP/Makefile
index 70094e5f..8d607c62 100644
--- a/regress/man/IP/Makefile
+++ b/regress/man/IP/Makefile
@@ -1,8 +1,9 @@
-# $OpenBSD: Makefile,v 1.10 2020/02/27 01:25:58 schwarze Exp $
+# $OpenBSD: Makefile,v 1.11 2020/03/13 00:31:05 schwarze Exp $
 
-REGRESS_TARGETS = bullet empty literal longhead manyargs spacing vert width
+REGRESS_TARGETS = bullet empty literal longhead manyargs spacing tag vert width
+TAG_TARGETS	= empty tag
 UTF8_TARGETS	= bullet
 LINT_TARGETS	= empty
-HTML_TARGETS	= bullet literal
+HTML_TARGETS	= bullet empty literal tag
 
 .include <bsd.regress.mk>
diff --git a/regress/man/IP/empty.in b/regress/man/IP/empty.in
index 21c42983..bb814870 100644
--- a/regress/man/IP/empty.in
+++ b/regress/man/IP/empty.in
@@ -1,8 +1,9 @@
-.\" $OpenBSD: empty.in,v 1.2 2017/07/04 14:53:23 schwarze Exp $
+.\" $OpenBSD: empty.in,v 1.3 2020/03/13 00:31:05 schwarze Exp $
 .TH IP-EMPTY 1 "July 17, 2012"
 .SH NAME
 IP-empty \- empty indented paragraphs
 .SH DESCRIPTION
+BEGINTEST
 regular
 text
 .IP
@@ -25,3 +26,4 @@ text
 .RE
 regular
 text
+ENDTEST
diff --git a/regress/man/IP/empty.out_ascii b/regress/man/IP/empty.out_ascii
index 24ab17fa..b17190ab 100644
--- a/regress/man/IP/empty.out_ascii
+++ b/regress/man/IP/empty.out_ascii
@@ -6,7 +6,7 @@ NNAAMMEE
        IP-empty - empty indented paragraphs
 
 DDEESSCCRRIIPPTTIIOONN
-       regular text
+       BEGINTEST regular text
 
               indented text
 
@@ -19,7 +19,7 @@ DDEESSCCRRIIPPTTIIOONN
        Empty IP is deleted, RS does not cause additional spacing:
 
               tag    indented text
-       regular text
+       regular text ENDTEST
 
 
 
diff --git a/regress/man/IP/empty.out_html b/regress/man/IP/empty.out_html
new file mode 100644
index 00000000..f2498dba
--- /dev/null
+++ b/regress/man/IP/empty.out_html
@@ -0,0 +1,18 @@
+<dl class="Bl-tag">
+  <dt></dt>
+  <dd>indented text</dd>
+</dl>
+<p class="Pp">Empty IP is deleted:</p>
+<dl class="Bl-tag">
+  <dt id="tag1"><a class="permalink" href="#tag1">tag1</a></dt>
+  <dd></dd>
+  <dt id="tag2"><a class="permalink" href="#tag2">tag2</a></dt>
+  <dd>indented text</dd>
+</dl>
+<p class="Pp">Empty IP is deleted, RS does not cause additional spacing:</p>
+<div class="Bd-indent">
+<dl class="Bl-tag">
+  <dt id="tag"><a class="permalink" href="#tag">tag</a></dt>
+  <dd>indented text</dd>
+</dl>
+</div>
diff --git a/regress/man/IP/empty.out_lint b/regress/man/IP/empty.out_lint
index 6c666c88..3514b94f 100644
--- a/regress/man/IP/empty.out_lint
+++ b/regress/man/IP/empty.out_lint
@@ -1,2 +1,2 @@
-mandoc: empty.in:13:2: WARNING: skipping paragraph macro: IP empty
-mandoc: empty.in:20:2: WARNING: skipping paragraph macro: IP empty
+mandoc: empty.in:14:2: WARNING: skipping paragraph macro: IP empty
+mandoc: empty.in:21:2: WARNING: skipping paragraph macro: IP empty
diff --git a/regress/man/IP/empty.out_tag b/regress/man/IP/empty.out_tag
new file mode 100644
index 00000000..f35f1120
--- /dev/null
+++ b/regress/man/IP/empty.out_tag
@@ -0,0 +1,3 @@
+tag1 15
+tag2 17
+tag 21
diff --git a/regress/man/IP/literal.out_html b/regress/man/IP/literal.out_html
index b61fc843..3b9cc429 100644
--- a/regress/man/IP/literal.out_html
+++ b/regress/man/IP/literal.out_html
@@ -1,5 +1,5 @@
 <dl class="Bl-tag">
-  <dt>tag</dt>
+  <dt id="tag"><a class="permalink" href="#tag">tag</a></dt>
   <dd>indented regular text</dd>
 </dl>
 <p class="Pp">new regular paragraph</p>
@@ -8,7 +8,7 @@ literal
 text
 </pre>
 <dl class="Bl-tag">
-  <dt>tag</dt>
+  <dt id="tag_2"><a class="permalink" href="#tag_2">tag</a></dt>
   <dd>
     <pre>
 indented
@@ -32,7 +32,7 @@ literal
 text
 </pre>
 <dl class="Bl-tag">
-  <dt>tag</dt>
+  <dt id="tag_3"><a class="permalink" href="#tag_3">tag</a></dt>
   <dd>
     <pre>
 indented
@@ -48,7 +48,7 @@ text
   out of indented paragraph</a></h2>
 <p class="Pp">regular text</p>
 <dl class="Bl-tag">
-  <dt>tag</dt>
+  <dt id="tag_4"><a class="permalink" href="#tag_4">tag</a></dt>
   <dd>indented regular text
     <pre>
 indented
diff --git a/regress/man/IP/tag.in b/regress/man/IP/tag.in
new file mode 100644
index 00000000..038fa969
--- /dev/null
+++ b/regress/man/IP/tag.in
@@ -0,0 +1,18 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:05 schwarze Exp $
+.TH IP-TAG 1 "March 10, 2020"
+.SH NAME
+IP-tag \- automatic tagging of indented blocks
+.SH DESCRIPTION
+BEGINTEST
+initial
+text
+.IP " strong" 10n
+text
+.IP "-strong"
+text
+.IP "\&\fI \-weak\fP"
+text
+.IP " strong"
+text
+.PP
+ENDTEST
diff --git a/regress/man/IP/tag.out_ascii b/regress/man/IP/tag.out_ascii
new file mode 100644
index 00000000..afd4f587
--- /dev/null
+++ b/regress/man/IP/tag.out_ascii
@@ -0,0 +1,23 @@
+IP-TAG(1)                   General Commands Manual                  IP-TAG(1)
+
+
+
+NNAAMMEE
+       IP-tag - automatic tagging of indented blocks
+
+DDEESSCCRRIIPPTTIIOONN
+       BEGINTEST initial text
+
+        strong   text
+
+       -strong   text
+
+        _-_w_e_a_k    text
+
+        strong   text
+
+       ENDTEST
+
+
+
+OpenBSD                         March 10, 2020                       IP-TAG(1)
diff --git a/regress/man/IP/tag.out_html b/regress/man/IP/tag.out_html
new file mode 100644
index 00000000..4d25b12b
--- /dev/null
+++ b/regress/man/IP/tag.out_html
@@ -0,0 +1,10 @@
+<dl class="Bl-tag">
+  <dt> strong</dt>
+  <dd>text</dd>
+  <dt id="strong"><a class="permalink" href="#strong">-strong</a></dt>
+  <dd>text</dd>
+  <dt id="weak"><a class="permalink" href="#weak"><i> -weak</i></a></dt>
+  <dd>text</dd>
+  <dt> strong</dt>
+  <dd>text</dd>
+</dl>
diff --git a/regress/man/IP/tag.out_tag b/regress/man/IP/tag.out_tag
new file mode 100644
index 00000000..5be038db
--- /dev/null
+++ b/regress/man/IP/tag.out_tag
@@ -0,0 +1,2 @@
+strong 13
+weak 15
diff --git a/regress/man/TP/Makefile b/regress/man/TP/Makefile
index ca2475b0..9dd2fde7 100644
--- a/regress/man/TP/Makefile
+++ b/regress/man/TP/Makefile
@@ -1,9 +1,10 @@
-# $OpenBSD: Makefile,v 1.16 2020/02/27 01:25:58 schwarze Exp $
+# $OpenBSD: Makefile,v 1.17 2020/03/13 00:31:05 schwarze Exp $
 
 REGRESS_TARGETS	 = badarg broken double eof fill indent literal longhead
-REGRESS_TARGETS	+= macrotag manyargs sameline spacing vert width
+REGRESS_TARGETS	+= macrotag manyargs sameline spacing tag vert width
+TAG_TARGETS	 = tag
 LINT_TARGETS	 = broken double eof
-HTML_TARGETS	 = literal vert
+HTML_TARGETS	 = literal tag vert
 
 # groff-1.22.3 defects:
 # - If .TP precedes .RE, the latter does not properly reset indentation.
diff --git a/regress/man/TP/literal.out_html b/regress/man/TP/literal.out_html
index 7f5b1c1f..8b818ed8 100644
--- a/regress/man/TP/literal.out_html
+++ b/regress/man/TP/literal.out_html
@@ -1,5 +1,5 @@
 <dl class="Bl-tag">
-  <dt>tag</dt>
+  <dt id="tag"><a class="permalink" href="#tag">tag</a></dt>
   <dd>regular indented text</dd>
 </dl>
 <p class="Pp">regular paragraph</p>
@@ -8,7 +8,7 @@ literal
 text
 </pre>
 <dl class="Bl-tag">
-  <dt>tag</dt>
+  <dt id="tag_2"><a class="permalink" href="#tag_2">tag</a></dt>
   <dd>
     <pre>
 indented
diff --git a/regress/man/TP/tag.in b/regress/man/TP/tag.in
new file mode 100644
index 00000000..34d1e151
--- /dev/null
+++ b/regress/man/TP/tag.in
@@ -0,0 +1,31 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:05 schwarze Exp $
+.TH IP-TAG 1 "March 10, 2020"
+.SH NAME
+IP-tag \- automatic tagging of indented blocks
+.SH DESCRIPTION
+BEGINTEST
+initial
+text
+.TP 10n
+.I " plain"
+text
+.TP
+plain
+text
+.TP
+.I "plain "
+text
+.TP
+\& strong
+text
+.TP
+.B -strong
+text
+.TP
+\&\fI \-weak\fP
+text
+.TP
+.B "strong "
+text
+.PP
+ENDTEST
diff --git a/regress/man/TP/tag.out_ascii b/regress/man/TP/tag.out_ascii
new file mode 100644
index 00000000..4da2efa0
--- /dev/null
+++ b/regress/man/TP/tag.out_ascii
@@ -0,0 +1,29 @@
+IP-TAG(1)                   General Commands Manual                  IP-TAG(1)
+
+
+
+NNAAMMEE
+       IP-tag - automatic tagging of indented blocks
+
+DDEESSCCRRIIPPTTIIOONN
+       BEGINTEST initial text
+
+        _p_l_a_i_n    text
+
+       plain     text
+
+       _p_l_a_i_n     text
+
+        strong   text
+
+       --ssttrroonngg   text
+
+        _-_w_e_a_k    text
+
+       ssttrroonngg    text
+
+       ENDTEST
+
+
+
+OpenBSD                         March 10, 2020                       IP-TAG(1)
diff --git a/regress/man/TP/tag.out_html b/regress/man/TP/tag.out_html
new file mode 100644
index 00000000..3fbbe41d
--- /dev/null
+++ b/regress/man/TP/tag.out_html
@@ -0,0 +1,16 @@
+<dl class="Bl-tag">
+  <dt><i> plain</i></dt>
+  <dd>text</dd>
+  <dt id="plain"><a class="permalink" href="#plain">plain</a></dt>
+  <dd>text</dd>
+  <dt><i>plain </i></dt>
+  <dd>text</dd>
+  <dt> strong</dt>
+  <dd>text</dd>
+  <dt id="strong"><a class="permalink" href="#strong"><b>-strong</b></a></dt>
+  <dd>text</dd>
+  <dt id="weak"><a class="permalink" href="#weak"><i> -weak</i></a></dt>
+  <dd>text</dd>
+  <dt><b>strong </b></dt>
+  <dd>text</dd>
+</dl>
diff --git a/regress/man/TP/tag.out_tag b/regress/man/TP/tag.out_tag
new file mode 100644
index 00000000..88f6cff8
--- /dev/null
+++ b/regress/man/TP/tag.out_tag
@@ -0,0 +1,3 @@
+plain 13
+strong 19
+weak 21
diff --git a/regress/man/TP/vert.out_html b/regress/man/TP/vert.out_html
index 7301819f..1124ed33 100644
--- a/regress/man/TP/vert.out_html
+++ b/regress/man/TP/vert.out_html
@@ -2,8 +2,8 @@
 <section class="Sh">
 <h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1>
 <dl class="Bl-tag">
-  <dt>tag</dt>
+  <dt id="tag"><a class="permalink" href="#tag">tag</a></dt>
   <dd>text</dd>
-  <dt>tag</dt>
+  <dt id="tag_2"><a class="permalink" href="#tag_2">tag</a></dt>
   <dd>text</dd>
 </dl>
diff --git a/regress/mdoc/Cm/Makefile b/regress/mdoc/Cm/Makefile
index 4b7066ec..7bc3fc20 100644
--- a/regress/mdoc/Cm/Makefile
+++ b/regress/mdoc/Cm/Makefile
@@ -1,6 +1,8 @@
-# $OpenBSD: Makefile,v 1.3 2014/07/02 20:18:42 schwarze Exp $
+# $OpenBSD: Makefile,v 1.7 2020/03/13 00:31:05 schwarze Exp $
 
-REGRESS_TARGETS = basic font noarg punct
+REGRESS_TARGETS = basic font noarg punct tag
+TAG_TARGETS	= tag
 LINT_TARGETS	= noarg
+HTML_TARGETS	= tag
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/Cm/tag.in b/regress/mdoc/Cm/tag.in
new file mode 100644
index 00000000..3db1d1e0
--- /dev/null
+++ b/regress/mdoc/Cm/tag.in
@@ -0,0 +1,21 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:05 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt CM-TAG 1
+.Os
+.Sh NAME
+.Nm Cm-tag
+.Nd tagging of command modifier macros
+.Sh DESCRIPTION
+BEGINTEST
+.Bl -tag -width Ds
+.It Cm one | two
+text
+.It Xo
+.Cm three
+.Xc
+text
+.El
+.Tg
+.Cm four
+.Pp
+ENDTEST
diff --git a/regress/mdoc/Cm/tag.out_ascii b/regress/mdoc/Cm/tag.out_ascii
new file mode 100644
index 00000000..071408c7
--- /dev/null
+++ b/regress/mdoc/Cm/tag.out_ascii
@@ -0,0 +1,17 @@
+CM-TAG(1)                   General Commands Manual                  CM-TAG(1)
+
+NNAAMMEE
+     CCmm--ttaagg - tagging of command modifier macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     oonnee | ttwwoo
+             text
+
+     tthhrreeee   text
+     ffoouurr
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Cm/tag.out_html b/regress/mdoc/Cm/tag.out_html
new file mode 100644
index 00000000..a140fe3e
--- /dev/null
+++ b/regress/mdoc/Cm/tag.out_html
@@ -0,0 +1,9 @@
+<dl class="Bl-tag">
+  <dt><a class="permalink" href="#one"><code class="Cm" id="one">one</code></a>
+    |
+    <a class="permalink" href="#two"><code class="Cm" id="two">two</code></a></dt>
+  <dd>text</dd>
+  <dt><a class="permalink" href="#three"><code class="Cm" id="three">three</code></a></dt>
+  <dd>text</dd>
+</dl>
+<a class="permalink" href="#four"><code class="Cm" id="four">four</code></a>
diff --git a/regress/mdoc/Cm/tag.out_markdown b/regress/mdoc/Cm/tag.out_markdown
new file mode 100644
index 00000000..893a8fe5
--- /dev/null
+++ b/regress/mdoc/Cm/tag.out_markdown
@@ -0,0 +1,23 @@
+CM-TAG(1) - General Commands Manual
+
+# NAME
+
+**Cm-tag** - tagging of command modifier macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+**one** | **two**
+
+> text
+
+**three**
+
+> text
+
+**four**
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Cm/tag.out_tag b/regress/mdoc/Cm/tag.out_tag
new file mode 100644
index 00000000..94f0cfb2
--- /dev/null
+++ b/regress/mdoc/Cm/tag.out_tag
@@ -0,0 +1,4 @@
+one 9
+two 9
+three 12
+four 13
diff --git a/regress/mdoc/Dv/Makefile b/regress/mdoc/Dv/Makefile
index cfe3ad0b..979e1826 100644
--- a/regress/mdoc/Dv/Makefile
+++ b/regress/mdoc/Dv/Makefile
@@ -1,6 +1,8 @@
-# $OpenBSD: Makefile,v 1.2 2014/07/02 20:18:42 schwarze Exp $
+# $OpenBSD: Makefile,v 1.5 2020/03/13 00:31:05 schwarze Exp $
 
-REGRESS_TARGETS	= font noarg
+REGRESS_TARGETS	= font noarg tag
+TAG_TARGETS	= tag
 LINT_TARGETS	= noarg
+HTML_TARGETS	= tag
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/Dv/tag.in b/regress/mdoc/Dv/tag.in
new file mode 100644
index 00000000..b6c79ad1
--- /dev/null
+++ b/regress/mdoc/Dv/tag.in
@@ -0,0 +1,21 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:05 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt DV-TAG 1
+.Os
+.Sh NAME
+.Nm Dv-tag
+.Nd tagging of defined variable macros
+.Sh DESCRIPTION
+BEGINTEST
+.Bl -tag -width Ds
+.It Dv one | two
+text
+.It Xo
+.Dv three
+.Xc
+text
+.El
+.Tg
+.Dv four
+.Pp
+ENDTEST
diff --git a/regress/mdoc/Dv/tag.out_ascii b/regress/mdoc/Dv/tag.out_ascii
new file mode 100644
index 00000000..119e3509
--- /dev/null
+++ b/regress/mdoc/Dv/tag.out_ascii
@@ -0,0 +1,17 @@
+DV-TAG(1)                   General Commands Manual                  DV-TAG(1)
+
+NNAAMMEE
+     DDvv--ttaagg - tagging of defined variable macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     one | two
+             text
+
+     three   text
+     four
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Dv/tag.out_html b/regress/mdoc/Dv/tag.out_html
new file mode 100644
index 00000000..cee78340
--- /dev/null
+++ b/regress/mdoc/Dv/tag.out_html
@@ -0,0 +1,9 @@
+<dl class="Bl-tag">
+  <dt><a class="permalink" href="#one"><code class="Dv" id="one">one</code></a>
+    |
+    <a class="permalink" href="#two"><code class="Dv" id="two">two</code></a></dt>
+  <dd>text</dd>
+  <dt><a class="permalink" href="#three"><code class="Dv" id="three">three</code></a></dt>
+  <dd>text</dd>
+</dl>
+<a class="permalink" href="#four"><code class="Dv" id="four">four</code></a>
diff --git a/regress/mdoc/Dv/tag.out_markdown b/regress/mdoc/Dv/tag.out_markdown
new file mode 100644
index 00000000..29b454bb
--- /dev/null
+++ b/regress/mdoc/Dv/tag.out_markdown
@@ -0,0 +1,23 @@
+DV-TAG(1) - General Commands Manual
+
+# NAME
+
+**Dv-tag** - tagging of defined variable macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+`one` | `two`
+
+> text
+
+`three`
+
+> text
+
+`four`
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Dv/tag.out_tag b/regress/mdoc/Dv/tag.out_tag
new file mode 100644
index 00000000..94f0cfb2
--- /dev/null
+++ b/regress/mdoc/Dv/tag.out_tag
@@ -0,0 +1,4 @@
+one 9
+two 9
+three 12
+four 13
diff --git a/regress/mdoc/Em/Makefile b/regress/mdoc/Em/Makefile
index 13de4337..2b500444 100644
--- a/regress/mdoc/Em/Makefile
+++ b/regress/mdoc/Em/Makefile
@@ -1,6 +1,8 @@
-# $OpenBSD: Makefile,v 1.3 2014/11/17 06:44:35 schwarze Exp $
+# $OpenBSD: Makefile,v 1.6 2020/03/13 00:31:05 schwarze Exp $
 
-REGRESS_TARGETS	= font noarg punct
+REGRESS_TARGETS	= font noarg punct tag
+TAG_TARGETS	= tag
 LINT_TARGETS	= noarg punct
+HTML_TARGETS	= tag
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/Em/tag.in b/regress/mdoc/Em/tag.in
new file mode 100644
index 00000000..70e6eb44
--- /dev/null
+++ b/regress/mdoc/Em/tag.in
@@ -0,0 +1,23 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:05 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt EM-TAG 1
+.Os
+.Sh NAME
+.Nm Em-tag
+.Nd tagging of emphasis macros
+.Sh DESCRIPTION
+BEGINTEST
+.Bl -tag -width Ds
+.It Em one | two
+text
+.It Xo
+.Em three
+.Xc
+text
+.El
+.Em four
+.Em one
+.Tg explicit
+.Em five
+.Pp
+ENDTEST
diff --git a/regress/mdoc/Em/tag.out_ascii b/regress/mdoc/Em/tag.out_ascii
new file mode 100644
index 00000000..74f8212b
--- /dev/null
+++ b/regress/mdoc/Em/tag.out_ascii
@@ -0,0 +1,17 @@
+EM-TAG(1)                   General Commands Manual                  EM-TAG(1)
+
+NNAAMMEE
+     EEmm--ttaagg - tagging of emphasis macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     _o_n_e | _t_w_o
+             text
+
+     _t_h_r_e_e   text
+     _f_o_u_r _o_n_e _f_i_v_e
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Em/tag.out_html b/regress/mdoc/Em/tag.out_html
new file mode 100644
index 00000000..4046673f
--- /dev/null
+++ b/regress/mdoc/Em/tag.out_html
@@ -0,0 +1,10 @@
+<dl class="Bl-tag">
+  <dt><a class="permalink" href="#one"><i class="Em" id="one">one</i></a> |
+    <a class="permalink" href="#two"><i class="Em" id="two">two</i></a></dt>
+  <dd>text</dd>
+  <dt><a class="permalink" href="#three"><i class="Em" id="three">three</i></a></dt>
+  <dd>text</dd>
+</dl>
+<a class="permalink" href="#four"><i class="Em" id="four">four</i></a>
+  <i class="Em">one</i>
+  <a class="permalink" href="#explicit"><i class="Em" id="explicit">five</i></a>
diff --git a/regress/mdoc/Em/tag.out_markdown b/regress/mdoc/Em/tag.out_markdown
new file mode 100644
index 00000000..4c107159
--- /dev/null
+++ b/regress/mdoc/Em/tag.out_markdown
@@ -0,0 +1,25 @@
+EM-TAG(1) - General Commands Manual
+
+# NAME
+
+**Em-tag** - tagging of emphasis macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+*one* | *two*
+
+> text
+
+*three*
+
+> text
+
+*four*
+*one*
+*five*
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Em/tag.out_tag b/regress/mdoc/Em/tag.out_tag
new file mode 100644
index 00000000..c2fbaf59
--- /dev/null
+++ b/regress/mdoc/Em/tag.out_tag
@@ -0,0 +1,5 @@
+one 9
+two 9
+three 12
+four 13
+explicit 13
diff --git a/regress/mdoc/Er/Makefile b/regress/mdoc/Er/Makefile
index 1be2a84a..55f6cc76 100644
--- a/regress/mdoc/Er/Makefile
+++ b/regress/mdoc/Er/Makefile
@@ -1,6 +1,8 @@
-# $OpenBSD: Makefile,v 1.4 2014/07/02 20:18:42 schwarze Exp $
+# $OpenBSD: Makefile,v 1.7 2020/03/13 00:31:05 schwarze Exp $
 
-REGRESS_TARGETS = noarg font
+REGRESS_TARGETS = noarg font tag
+TAG_TARGETS	= tag
 LINT_TARGETS	= noarg
+HTML_TARGETS	= tag
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/Er/tag.in b/regress/mdoc/Er/tag.in
new file mode 100644
index 00000000..4227648b
--- /dev/null
+++ b/regress/mdoc/Er/tag.in
@@ -0,0 +1,21 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:05 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt ER-TAG 1
+.Os
+.Sh NAME
+.Nm Er-tag
+.Nd tagging of error number macros
+.Sh DESCRIPTION
+BEGINTEST
+.Bl -tag -width Ds
+.It Er one
+text
+.El
+.Tg
+.Er two
+.Sh ERRORS
+.Bl -tag -width Er
+.It Bq Er ENOENT
+text
+.El
+ENDTEST
diff --git a/regress/mdoc/Er/tag.out_ascii b/regress/mdoc/Er/tag.out_ascii
new file mode 100644
index 00000000..62dbf9ca
--- /dev/null
+++ b/regress/mdoc/Er/tag.out_ascii
@@ -0,0 +1,16 @@
+ER-TAG(1)                   General Commands Manual                  ER-TAG(1)
+
+NNAAMMEE
+     EErr--ttaagg - tagging of error number macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     one     text
+     two
+
+EERRRROORRSS
+     [ENOENT]           text
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Er/tag.out_html b/regress/mdoc/Er/tag.out_html
new file mode 100644
index 00000000..a2c2978f
--- /dev/null
+++ b/regress/mdoc/Er/tag.out_html
@@ -0,0 +1,12 @@
+<dl class="Bl-tag">
+  <dt><code class="Er">one</code></dt>
+  <dd>text</dd>
+</dl>
+<a class="permalink" href="#two"><code class="Er" id="two">two</code></a>
+</section>
+<section class="Sh">
+<h1 class="Sh" id="ERRORS"><a class="permalink" href="#ERRORS">ERRORS</a></h1>
+<dl class="Bl-tag">
+  <dt>[<a class="permalink" href="#ENOENT"><code class="Er" id="ENOENT">ENOENT</code></a>]</dt>
+  <dd>text</dd>
+</dl>
diff --git a/regress/mdoc/Er/tag.out_markdown b/regress/mdoc/Er/tag.out_markdown
new file mode 100644
index 00000000..d11eb4b9
--- /dev/null
+++ b/regress/mdoc/Er/tag.out_markdown
@@ -0,0 +1,25 @@
+ER-TAG(1) - General Commands Manual
+
+# NAME
+
+**Er-tag** - tagging of error number macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+`one`
+
+> text
+
+`two`
+
+# ERRORS
+
+\[`ENOENT`]
+
+> text
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Er/tag.out_tag b/regress/mdoc/Er/tag.out_tag
new file mode 100644
index 00000000..b00a6718
--- /dev/null
+++ b/regress/mdoc/Er/tag.out_tag
@@ -0,0 +1,2 @@
+two 10
+ENOENT 13
diff --git a/regress/mdoc/Ev/Makefile b/regress/mdoc/Ev/Makefile
index cfe3ad0b..979e1826 100644
--- a/regress/mdoc/Ev/Makefile
+++ b/regress/mdoc/Ev/Makefile
@@ -1,6 +1,8 @@
-# $OpenBSD: Makefile,v 1.2 2014/07/02 20:18:42 schwarze Exp $
+# $OpenBSD: Makefile,v 1.5 2020/03/13 00:31:05 schwarze Exp $
 
-REGRESS_TARGETS	= font noarg
+REGRESS_TARGETS	= font noarg tag
+TAG_TARGETS	= tag
 LINT_TARGETS	= noarg
+HTML_TARGETS	= tag
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/Ev/tag.in b/regress/mdoc/Ev/tag.in
new file mode 100644
index 00000000..2627fdeb
--- /dev/null
+++ b/regress/mdoc/Ev/tag.in
@@ -0,0 +1,21 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:05 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt EV-TAG 1
+.Os
+.Sh NAME
+.Nm Ev-tag
+.Nd tagging of environment variable macros
+.Sh DESCRIPTION
+BEGINTEST
+.Bl -tag -width Ds
+.It Ev one | two
+text
+.It Xo
+.Ev three
+.Xc
+text
+.El
+.Tg
+.Ev four
+.Pp
+ENDTEST
diff --git a/regress/mdoc/Ev/tag.out_ascii b/regress/mdoc/Ev/tag.out_ascii
new file mode 100644
index 00000000..5569d1c8
--- /dev/null
+++ b/regress/mdoc/Ev/tag.out_ascii
@@ -0,0 +1,17 @@
+EV-TAG(1)                   General Commands Manual                  EV-TAG(1)
+
+NNAAMMEE
+     EEvv--ttaagg - tagging of environment variable macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     one | two
+             text
+
+     three   text
+     four
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Ev/tag.out_html b/regress/mdoc/Ev/tag.out_html
new file mode 100644
index 00000000..1e1c92b9
--- /dev/null
+++ b/regress/mdoc/Ev/tag.out_html
@@ -0,0 +1,9 @@
+<dl class="Bl-tag">
+  <dt><a class="permalink" href="#one"><code class="Ev" id="one">one</code></a>
+    |
+    <a class="permalink" href="#two"><code class="Ev" id="two">two</code></a></dt>
+  <dd>text</dd>
+  <dt><a class="permalink" href="#three"><code class="Ev" id="three">three</code></a></dt>
+  <dd>text</dd>
+</dl>
+<a class="permalink" href="#four"><code class="Ev" id="four">four</code></a>
diff --git a/regress/mdoc/Ev/tag.out_markdown b/regress/mdoc/Ev/tag.out_markdown
new file mode 100644
index 00000000..f9a6712b
--- /dev/null
+++ b/regress/mdoc/Ev/tag.out_markdown
@@ -0,0 +1,23 @@
+EV-TAG(1) - General Commands Manual
+
+# NAME
+
+**Ev-tag** - tagging of environment variable macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+`one` | `two`
+
+> text
+
+`three`
+
+> text
+
+`four`
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Ev/tag.out_tag b/regress/mdoc/Ev/tag.out_tag
new file mode 100644
index 00000000..94f0cfb2
--- /dev/null
+++ b/regress/mdoc/Ev/tag.out_tag
@@ -0,0 +1,4 @@
+one 9
+two 9
+three 12
+four 13
diff --git a/regress/mdoc/Fl/Makefile b/regress/mdoc/Fl/Makefile
index e4e4a6bc..c061adef 100644
--- a/regress/mdoc/Fl/Makefile
+++ b/regress/mdoc/Fl/Makefile
@@ -1,6 +1,9 @@
-# $OpenBSD: Makefile,v 1.13 2020/02/27 01:25:58 schwarze Exp $
+# $OpenBSD: Makefile,v 1.14 2020/03/13 00:31:06 schwarze Exp $
 
-REGRESS_TARGETS = font multiarg noarg parsed punct spacing
+REGRESS_TARGETS = font multiarg noarg parsed punct spacing tag
+TAG_TARGETS	= tag
 LINT_TARGETS	= punct
+HTML_TARGETS	= tag
+SKIP_TMAN	= tag
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/Fl/tag.in b/regress/mdoc/Fl/tag.in
new file mode 100644
index 00000000..f7e24b9f
--- /dev/null
+++ b/regress/mdoc/Fl/tag.in
@@ -0,0 +1,21 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:06 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt FL-TAG 1
+.Os
+.Sh NAME
+.Nm Fl-tag
+.Nd tagging of command line option macros
+.Sh DESCRIPTION
+BEGINTEST
+.Bl -tag -width Ds
+.It Fl a | b
+text
+.It Xo
+.Fl c
+.Xc
+text
+.El
+.Tg
+.Fl d
+.Pp
+ENDTEST
diff --git a/regress/mdoc/Fl/tag.out_ascii b/regress/mdoc/Fl/tag.out_ascii
new file mode 100644
index 00000000..4fcf803c
--- /dev/null
+++ b/regress/mdoc/Fl/tag.out_ascii
@@ -0,0 +1,17 @@
+FL-TAG(1)                   General Commands Manual                  FL-TAG(1)
+
+NNAAMMEE
+     FFll--ttaagg - tagging of command line option macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     --aa | --bb
+             text
+
+     --cc      text
+     --dd
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Fl/tag.out_html b/regress/mdoc/Fl/tag.out_html
new file mode 100644
index 00000000..f67a30c0
--- /dev/null
+++ b/regress/mdoc/Fl/tag.out_html
@@ -0,0 +1,8 @@
+<dl class="Bl-tag">
+  <dt><a class="permalink" href="#a"><code class="Fl" id="a">-a</code></a> |
+    <a class="permalink" href="#b"><code class="Fl" id="b">-b</code></a></dt>
+  <dd>text</dd>
+  <dt><a class="permalink" href="#c"><code class="Fl" id="c">-c</code></a></dt>
+  <dd>text</dd>
+</dl>
+<a class="permalink" href="#d"><code class="Fl" id="d">-d</code></a>
diff --git a/regress/mdoc/Fl/tag.out_markdown b/regress/mdoc/Fl/tag.out_markdown
new file mode 100644
index 00000000..1e7c6f14
--- /dev/null
+++ b/regress/mdoc/Fl/tag.out_markdown
@@ -0,0 +1,23 @@
+FL-TAG(1) - General Commands Manual
+
+# NAME
+
+**Fl-tag** - tagging of command line option macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+**-a** | **-b**
+
+> text
+
+**-c**
+
+> text
+
+**-d**
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Fl/tag.out_tag b/regress/mdoc/Fl/tag.out_tag
new file mode 100644
index 00000000..89a94151
--- /dev/null
+++ b/regress/mdoc/Fl/tag.out_tag
@@ -0,0 +1,4 @@
+a 9
+b 9
+c 12
+d 13
diff --git a/regress/mdoc/Fo/Makefile b/regress/mdoc/Fo/Makefile
index 7770e9a1..ce25ddf3 100644
--- a/regress/mdoc/Fo/Makefile
+++ b/regress/mdoc/Fo/Makefile
@@ -1,8 +1,10 @@
-# $OpenBSD: Makefile,v 1.17 2020/02/27 01:25:58 schwarze Exp $
+# $OpenBSD: Makefile,v 1.18 2020/03/13 00:31:06 schwarze Exp $
 
 REGRESS_TARGETS	 = basic break eos font noarg nohead
-REGRESS_TARGETS += obsolete punct section transp warn
+REGRESS_TARGETS += obsolete punct section tag transp warn
+TAG_TARGETS	 = tag
 LINT_TARGETS	 = noarg nohead obsolete punct warn
+HTML_TARGETS	 = tag
 
 # groff-1.22.3 defects:
 # - .Fo without an argument prints unbalanced parentheses
diff --git a/regress/mdoc/Fo/tag.in b/regress/mdoc/Fo/tag.in
new file mode 100644
index 00000000..29b84ffe
--- /dev/null
+++ b/regress/mdoc/Fo/tag.in
@@ -0,0 +1,29 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:06 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt FO-TAG 1
+.Os
+.Sh NAME
+.Nm Fo-tag
+.Nd tagging of function name macros
+.Sh DESCRIPTION
+BEGINTEST
+.Pp
+automatic:
+.Fn first
+and
+.Fn second
+.Pp
+.Fn second
+and
+.Fn first
+.Pp
+explicit:
+.Tg e3
+.Fn third
+and
+.Tg e4
+.Fo fourth
+.Fa void
+.Fc
+.Pp
+ENDTEST
diff --git a/regress/mdoc/Fo/tag.out_ascii b/regress/mdoc/Fo/tag.out_ascii
new file mode 100644
index 00000000..505c0b7a
--- /dev/null
+++ b/regress/mdoc/Fo/tag.out_ascii
@@ -0,0 +1,17 @@
+FO-TAG(1)                   General Commands Manual                  FO-TAG(1)
+
+NNAAMMEE
+     FFoo--ttaagg - tagging of function name macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     automatic: ffiirrsstt() and sseeccoonndd()
+
+     sseeccoonndd() and ffiirrsstt()
+
+     explicit: tthhiirrdd() and ffoouurrtthh(_v_o_i_d)
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Fo/tag.out_html b/regress/mdoc/Fo/tag.out_html
new file mode 100644
index 00000000..b3508614
--- /dev/null
+++ b/regress/mdoc/Fo/tag.out_html
@@ -0,0 +1,9 @@
+<p class="Pp">automatic:
+    <a class="permalink" href="#first"><code class="Fn" id="first">first</code></a>()
+    and <code class="Fn">second</code>()</p>
+<p class="Pp"><a class="permalink" href="#second"><code class="Fn" id="second">second</code></a>()
+    and <code class="Fn">first</code>()</p>
+<p class="Pp">explicit:
+    <a class="permalink" href="#e3"><code class="Fn" id="e3">third</code></a>()
+    and
+    <a class="permalink" href="#e4"><code class="Fn" id="e4">fourth</code></a>(<var class="Fa">void</var>);</p>
diff --git a/regress/mdoc/Fo/tag.out_markdown b/regress/mdoc/Fo/tag.out_markdown
new file mode 100644
index 00000000..273a00d4
--- /dev/null
+++ b/regress/mdoc/Fo/tag.out_markdown
@@ -0,0 +1,27 @@
+FO-TAG(1) - General Commands Manual
+
+# NAME
+
+**Fo-tag** - tagging of function name macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+automatic:
+**first**()
+and
+**second**()
+
+**second**()
+and
+**first**()
+
+explicit:
+**third**()
+and
+**fourth**(*void*)
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Fo/tag.out_tag b/regress/mdoc/Fo/tag.out_tag
new file mode 100644
index 00000000..2387023c
--- /dev/null
+++ b/regress/mdoc/Fo/tag.out_tag
@@ -0,0 +1,4 @@
+first 9
+second 11
+e3 13
+e4 13
diff --git a/regress/mdoc/Ic/Makefile b/regress/mdoc/Ic/Makefile
index 33faa380..4a06ee20 100644
--- a/regress/mdoc/Ic/Makefile
+++ b/regress/mdoc/Ic/Makefile
@@ -1,6 +1,8 @@
-# $OpenBSD: Makefile,v 1.4 2014/07/02 20:18:42 schwarze Exp $
+# $OpenBSD: Makefile,v 1.8 2020/03/13 00:31:06 schwarze Exp $
 
-REGRESS_TARGETS = font noarg punct
+REGRESS_TARGETS = font noarg punct tag
+TAG_TARGETS	= tag
 LINT_TARGETS	= noarg
+HTML_TARGETS	= tag
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/Ic/tag.in b/regress/mdoc/Ic/tag.in
new file mode 100644
index 00000000..9d21426e
--- /dev/null
+++ b/regress/mdoc/Ic/tag.in
@@ -0,0 +1,21 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:06 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt IC-TAG 1
+.Os
+.Sh NAME
+.Nm Ic-tag
+.Nd tagging of internal command macros
+.Sh DESCRIPTION
+BEGINTEST
+.Bl -tag -width Ds
+.It Ic one | two
+text
+.It Xo
+.Ic three
+.Xc
+text
+.El
+.Tg
+.Ic four
+.Pp
+ENDTEST
diff --git a/regress/mdoc/Ic/tag.out_ascii b/regress/mdoc/Ic/tag.out_ascii
new file mode 100644
index 00000000..513b2638
--- /dev/null
+++ b/regress/mdoc/Ic/tag.out_ascii
@@ -0,0 +1,17 @@
+IC-TAG(1)                   General Commands Manual                  IC-TAG(1)
+
+NNAAMMEE
+     IIcc--ttaagg - tagging of internal command macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     oonnee | ttwwoo
+             text
+
+     tthhrreeee   text
+     ffoouurr
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Ic/tag.out_html b/regress/mdoc/Ic/tag.out_html
new file mode 100644
index 00000000..ad3cc1ef
--- /dev/null
+++ b/regress/mdoc/Ic/tag.out_html
@@ -0,0 +1,9 @@
+<dl class="Bl-tag">
+  <dt><a class="permalink" href="#one"><code class="Ic" id="one">one</code></a>
+    |
+    <a class="permalink" href="#two"><code class="Ic" id="two">two</code></a></dt>
+  <dd>text</dd>
+  <dt><a class="permalink" href="#three"><code class="Ic" id="three">three</code></a></dt>
+  <dd>text</dd>
+</dl>
+<a class="permalink" href="#four"><code class="Ic" id="four">four</code></a>
diff --git a/regress/mdoc/Ic/tag.out_markdown b/regress/mdoc/Ic/tag.out_markdown
new file mode 100644
index 00000000..c0f13879
--- /dev/null
+++ b/regress/mdoc/Ic/tag.out_markdown
@@ -0,0 +1,23 @@
+IC-TAG(1) - General Commands Manual
+
+# NAME
+
+**Ic-tag** - tagging of internal command macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+**one** | **two**
+
+> text
+
+**three**
+
+> text
+
+**four**
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Ic/tag.out_tag b/regress/mdoc/Ic/tag.out_tag
new file mode 100644
index 00000000..94f0cfb2
--- /dev/null
+++ b/regress/mdoc/Ic/tag.out_tag
@@ -0,0 +1,4 @@
+one 9
+two 9
+three 12
+four 13
diff --git a/regress/mdoc/Li/Makefile b/regress/mdoc/Li/Makefile
index 7b2a3313..44dcf01c 100644
--- a/regress/mdoc/Li/Makefile
+++ b/regress/mdoc/Li/Makefile
@@ -1,6 +1,8 @@
-# $OpenBSD: Makefile,v 1.7 2018/12/21 16:58:49 schwarze Exp $
+# $OpenBSD: Makefile,v 1.8 2020/03/13 00:31:06 schwarze Exp $
 
-REGRESS_TARGETS = arg punct font
+REGRESS_TARGETS = arg punct font tag
+TAG_TARGETS	= tag
 LINT_TARGETS	= punct
+HTML_TARGETS	= tag
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/Li/tag.in b/regress/mdoc/Li/tag.in
new file mode 100644
index 00000000..0ee9ce82
--- /dev/null
+++ b/regress/mdoc/Li/tag.in
@@ -0,0 +1,21 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:06 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt LI-TAG 1
+.Os
+.Sh NAME
+.Nm Li-tag
+.Nd tagging of literal font macros
+.Sh DESCRIPTION
+BEGINTEST
+.Bl -tag -width Ds
+.It Li one | two
+text
+.It Xo
+.Li three
+.Xc
+text
+.El
+.Tg
+.Li four
+.Pp
+ENDTEST
diff --git a/regress/mdoc/Li/tag.out_ascii b/regress/mdoc/Li/tag.out_ascii
new file mode 100644
index 00000000..e1afda6e
--- /dev/null
+++ b/regress/mdoc/Li/tag.out_ascii
@@ -0,0 +1,17 @@
+LI-TAG(1)                   General Commands Manual                  LI-TAG(1)
+
+NNAAMMEE
+     LLii--ttaagg - tagging of literal font macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     one | two
+             text
+
+     three   text
+     four
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Li/tag.out_html b/regress/mdoc/Li/tag.out_html
new file mode 100644
index 00000000..3730caa6
--- /dev/null
+++ b/regress/mdoc/Li/tag.out_html
@@ -0,0 +1,9 @@
+<dl class="Bl-tag">
+  <dt><a class="permalink" href="#one"><code class="Li" id="one">one</code></a>
+    |
+    <a class="permalink" href="#two"><code class="Li" id="two">two</code></a></dt>
+  <dd>text</dd>
+  <dt><a class="permalink" href="#three"><code class="Li" id="three">three</code></a></dt>
+  <dd>text</dd>
+</dl>
+<a class="permalink" href="#four"><code class="Li" id="four">four</code></a>
diff --git a/regress/mdoc/Li/tag.out_markdown b/regress/mdoc/Li/tag.out_markdown
new file mode 100644
index 00000000..6467e16d
--- /dev/null
+++ b/regress/mdoc/Li/tag.out_markdown
@@ -0,0 +1,23 @@
+LI-TAG(1) - General Commands Manual
+
+# NAME
+
+**Li-tag** - tagging of literal font macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+`one` | `two`
+
+> text
+
+`three`
+
+> text
+
+`four`
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Li/tag.out_tag b/regress/mdoc/Li/tag.out_tag
new file mode 100644
index 00000000..94f0cfb2
--- /dev/null
+++ b/regress/mdoc/Li/tag.out_tag
@@ -0,0 +1,4 @@
+one 9
+two 9
+three 12
+four 13
diff --git a/regress/mdoc/Makefile b/regress/mdoc/Makefile
index 86bdcb7a..83bd7fb7 100644
--- a/regress/mdoc/Makefile
+++ b/regress/mdoc/Makefile
@@ -1,9 +1,9 @@
-# $OpenBSD: Makefile,v 1.32 2017/01/11 17:39:45 schwarze Exp $
+# $OpenBSD: Makefile,v 1.33 2020/03/13 00:31:05 schwarze Exp $
 
 SUBDIR  = Ad An Ap Aq Ar At Bd Bf Bk Bl Brq Bx Cd Cm
 SUBDIR += D1 Db Dd Dl Dq Dt Dv Em Eo Er Ev Ex Fd Fl Fo Ft Ic In Lb Li Lk
 SUBDIR += Ms Mt Nd Nm No Ns Oo Op Os Ox Pa Pf Pp Qq Rs Rv
-SUBDIR += Sh Sm Sq St Sx Sy Tn Ud Ux Va Vt Xr blank break
+SUBDIR += Sh Sm Sq St Sx Sy Tg Tn Ud Ux Va Vt Xr blank break
 
 .include "../Makefile.sub"
 .include <bsd.subdir.mk>
diff --git a/regress/mdoc/Ms/Makefile b/regress/mdoc/Ms/Makefile
index 1be2a84a..618edd3f 100644
--- a/regress/mdoc/Ms/Makefile
+++ b/regress/mdoc/Ms/Makefile
@@ -1,6 +1,8 @@
-# $OpenBSD: Makefile,v 1.4 2014/07/02 20:18:42 schwarze Exp $
+# $OpenBSD: Makefile,v 1.8 2020/03/13 00:58:48 schwarze Exp $
 
-REGRESS_TARGETS = noarg font
+REGRESS_TARGETS = noarg font tag
+TAG_TARGETS	= tag
 LINT_TARGETS	= noarg
+HTML_TARGETS	= tag
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/Ms/tag.in b/regress/mdoc/Ms/tag.in
new file mode 100644
index 00000000..da65a07e
--- /dev/null
+++ b/regress/mdoc/Ms/tag.in
@@ -0,0 +1,21 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:06 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt MS-TAG 1
+.Os
+.Sh NAME
+.Nm Ms-tag
+.Nd tagging of mathematical symbol macros
+.Sh DESCRIPTION
+BEGINTEST
+.Bl -tag -width Ds
+.It Ms one | two
+text
+.It Xo
+.Ms three
+.Xc
+text
+.El
+.Tg
+.Ms four
+.Pp
+ENDTEST
diff --git a/regress/mdoc/Ms/tag.out_ascii b/regress/mdoc/Ms/tag.out_ascii
new file mode 100644
index 00000000..2d06f4bf
--- /dev/null
+++ b/regress/mdoc/Ms/tag.out_ascii
@@ -0,0 +1,17 @@
+MS-TAG(1)                   General Commands Manual                  MS-TAG(1)
+
+NNAAMMEE
+     MMss--ttaagg - tagging of mathematical symbol macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     oonnee | ttwwoo
+             text
+
+     tthhrreeee   text
+     ffoouurr
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Ms/tag.out_html b/regress/mdoc/Ms/tag.out_html
new file mode 100644
index 00000000..0f24b2ac
--- /dev/null
+++ b/regress/mdoc/Ms/tag.out_html
@@ -0,0 +1,9 @@
+<dl class="Bl-tag">
+  <dt><a class="permalink" href="#one"><span class="Ms" id="one">one</span></a>
+    |
+    <a class="permalink" href="#two"><span class="Ms" id="two">two</span></a></dt>
+  <dd>text</dd>
+  <dt><a class="permalink" href="#three"><span class="Ms" id="three">three</span></a></dt>
+  <dd>text</dd>
+</dl>
+<a class="permalink" href="#four"><span class="Ms" id="four">four</span></a>
diff --git a/regress/mdoc/Ms/tag.out_markdown b/regress/mdoc/Ms/tag.out_markdown
new file mode 100644
index 00000000..055c3860
--- /dev/null
+++ b/regress/mdoc/Ms/tag.out_markdown
@@ -0,0 +1,23 @@
+MS-TAG(1) - General Commands Manual
+
+# NAME
+
+**Ms-tag** - tagging of mathematical symbol macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+**one** | **two**
+
+> text
+
+**three**
+
+> text
+
+**four**
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Ms/tag.out_tag b/regress/mdoc/Ms/tag.out_tag
new file mode 100644
index 00000000..94f0cfb2
--- /dev/null
+++ b/regress/mdoc/Ms/tag.out_tag
@@ -0,0 +1,4 @@
+one 9
+two 9
+three 12
+four 13
diff --git a/regress/mdoc/No/Makefile b/regress/mdoc/No/Makefile
index 3110bf2b..35aa4e1e 100644
--- a/regress/mdoc/No/Makefile
+++ b/regress/mdoc/No/Makefile
@@ -1,6 +1,8 @@
-# $OpenBSD: Makefile,v 1.4 2014/11/17 06:44:35 schwarze Exp $
+# $OpenBSD: Makefile,v 1.7 2020/03/13 00:31:06 schwarze Exp $
 
-REGRESS_TARGETS = punct spacing
+REGRESS_TARGETS = punct spacing tag
+TAG_TARGETS	= tag
 LINT_TARGETS	= punct
+HTML_TARGETS	= tag
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/No/punct.out_lint b/regress/mdoc/No/punct.out_lint
index e046da6a..6a65c3b4 100644
--- a/regress/mdoc/No/punct.out_lint
+++ b/regress/mdoc/No/punct.out_lint
@@ -23,3 +23,4 @@ mandoc: punct.in:72:7: WARNING: skipping empty macro: No
 mandoc: punct.in:75:7: WARNING: skipping empty macro: No
 mandoc: punct.in:76:7: WARNING: skipping empty macro: No
 mandoc: punct.in:84:2: WARNING: skipping empty macro: No
+mandoc: punct.in:87:6: STYLE: no blank before trailing delimiter: No a.
diff --git a/regress/mdoc/No/tag.in b/regress/mdoc/No/tag.in
new file mode 100644
index 00000000..a9d4415f
--- /dev/null
+++ b/regress/mdoc/No/tag.in
@@ -0,0 +1,21 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:06 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt NO-TAG 1
+.Os
+.Sh NAME
+.Nm No-tag
+.Nd tagging of normal font macros
+.Sh DESCRIPTION
+BEGINTEST
+.Bl -tag -width Ds
+.It No one | two
+text
+.It Xo
+.No three
+.Xc
+text
+.El
+.Tg
+.No four
+.Pp
+ENDTEST
diff --git a/regress/mdoc/No/tag.out_ascii b/regress/mdoc/No/tag.out_ascii
new file mode 100644
index 00000000..44481b02
--- /dev/null
+++ b/regress/mdoc/No/tag.out_ascii
@@ -0,0 +1,17 @@
+NO-TAG(1)                   General Commands Manual                  NO-TAG(1)
+
+NNAAMMEE
+     NNoo--ttaagg - tagging of normal font macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     one | two
+             text
+
+     three   text
+     four
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/No/tag.out_html b/regress/mdoc/No/tag.out_html
new file mode 100644
index 00000000..32696917
--- /dev/null
+++ b/regress/mdoc/No/tag.out_html
@@ -0,0 +1,9 @@
+<dl class="Bl-tag">
+  <dt><a class="permalink" href="#one"><span class="No" id="one">one</span></a>
+    |
+    <a class="permalink" href="#two"><span class="No" id="two">two</span></a></dt>
+  <dd>text</dd>
+  <dt><a class="permalink" href="#three"><span class="No" id="three">three</span></a></dt>
+  <dd>text</dd>
+</dl>
+<a class="permalink" href="#four"><span class="No" id="four">four</span></a>
diff --git a/regress/mdoc/No/tag.out_markdown b/regress/mdoc/No/tag.out_markdown
new file mode 100644
index 00000000..1590c010
--- /dev/null
+++ b/regress/mdoc/No/tag.out_markdown
@@ -0,0 +1,23 @@
+NO-TAG(1) - General Commands Manual
+
+# NAME
+
+**No-tag** - tagging of normal font macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+one | two
+
+> text
+
+three
+
+> text
+
+four
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/No/tag.out_tag b/regress/mdoc/No/tag.out_tag
new file mode 100644
index 00000000..94f0cfb2
--- /dev/null
+++ b/regress/mdoc/No/tag.out_tag
@@ -0,0 +1,4 @@
+one 9
+two 9
+three 12
+four 13
diff --git a/regress/mdoc/Sy/Makefile b/regress/mdoc/Sy/Makefile
index 36c1859b..752d1382 100644
--- a/regress/mdoc/Sy/Makefile
+++ b/regress/mdoc/Sy/Makefile
@@ -1,6 +1,8 @@
-# $OpenBSD: Makefile,v 1.5 2014/11/17 06:44:35 schwarze Exp $
+# $OpenBSD: Makefile,v 1.8 2020/03/13 00:31:06 schwarze Exp $
 
-REGRESS_TARGETS = noarg font punct
+REGRESS_TARGETS = noarg font punct tag
+TAG_TARGETS	= tag
 LINT_TARGETS	= noarg punct
+HTML_TARGETS	= tag
 
 .include <bsd.regress.mk>
diff --git a/regress/mdoc/Sy/tag.in b/regress/mdoc/Sy/tag.in
new file mode 100644
index 00000000..1294e17d
--- /dev/null
+++ b/regress/mdoc/Sy/tag.in
@@ -0,0 +1,23 @@
+.\" $OpenBSD: tag.in,v 1.1 2020/03/13 00:31:06 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt SY-TAG 1
+.Os
+.Sh NAME
+.Nm Sy-tag
+.Nd tagging of symbolic font macros
+.Sh DESCRIPTION
+BEGINTEST
+.Bl -tag -width Ds
+.It Sy one | two
+text
+.It Xo
+.Sy three
+.Xc
+text
+.El
+.Sy four
+.Sy one
+.Tg explicit
+.Sy five
+.Pp
+ENDTEST
diff --git a/regress/mdoc/Sy/tag.out_ascii b/regress/mdoc/Sy/tag.out_ascii
new file mode 100644
index 00000000..3b89cb41
--- /dev/null
+++ b/regress/mdoc/Sy/tag.out_ascii
@@ -0,0 +1,17 @@
+SY-TAG(1)                   General Commands Manual                  SY-TAG(1)
+
+NNAAMMEE
+     SSyy--ttaagg - tagging of symbolic font macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     oonnee | ttwwoo
+             text
+
+     tthhrreeee   text
+     ffoouurr oonnee ffiivvee
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Sy/tag.out_html b/regress/mdoc/Sy/tag.out_html
new file mode 100644
index 00000000..69276a18
--- /dev/null
+++ b/regress/mdoc/Sy/tag.out_html
@@ -0,0 +1,10 @@
+<dl class="Bl-tag">
+  <dt><a class="permalink" href="#one"><b class="Sy" id="one">one</b></a> |
+    <a class="permalink" href="#two"><b class="Sy" id="two">two</b></a></dt>
+  <dd>text</dd>
+  <dt><a class="permalink" href="#three"><b class="Sy" id="three">three</b></a></dt>
+  <dd>text</dd>
+</dl>
+<a class="permalink" href="#four"><b class="Sy" id="four">four</b></a>
+  <b class="Sy">one</b>
+  <a class="permalink" href="#explicit"><b class="Sy" id="explicit">five</b></a>
diff --git a/regress/mdoc/Sy/tag.out_markdown b/regress/mdoc/Sy/tag.out_markdown
new file mode 100644
index 00000000..5382a5e2
--- /dev/null
+++ b/regress/mdoc/Sy/tag.out_markdown
@@ -0,0 +1,25 @@
+SY-TAG(1) - General Commands Manual
+
+# NAME
+
+**Sy-tag** - tagging of symbolic font macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+**one** | **two**
+
+> text
+
+**three**
+
+> text
+
+**four**
+**one**
+**five**
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Sy/tag.out_tag b/regress/mdoc/Sy/tag.out_tag
new file mode 100644
index 00000000..c2fbaf59
--- /dev/null
+++ b/regress/mdoc/Sy/tag.out_tag
@@ -0,0 +1,5 @@
+one 9
+two 9
+three 12
+four 13
+explicit 13
diff --git a/regress/mdoc/Tg/Makefile b/regress/mdoc/Tg/Makefile
new file mode 100644
index 00000000..7f538766
--- /dev/null
+++ b/regress/mdoc/Tg/Makefile
@@ -0,0 +1,8 @@
+# $OpenBSD: Makefile,v 1.1 2020/03/13 00:31:06 schwarze Exp $
+
+REGRESS_TARGETS = warn
+TAG_TARGETS	= warn
+LINT_TARGETS	= warn
+HTML_TARGETS	= warn
+
+.include <bsd.regress.mk>
diff --git a/regress/mdoc/Tg/warn.in b/regress/mdoc/Tg/warn.in
new file mode 100644
index 00000000..e36f4506
--- /dev/null
+++ b/regress/mdoc/Tg/warn.in
@@ -0,0 +1,34 @@
+.\" $OpenBSD: warn.in,v 1.1 2020/03/13 00:31:06 schwarze Exp $
+.Dd $Mdocdate: March 13 2020 $
+.Dt TG-WARN 1
+.Os
+.Sh NAME
+.Nm Tg-warn
+.Nd warnings about tagging macros
+.Sh DESCRIPTION
+BEGINTEST
+.Pp
+.Tg start
+initial
+text
+.Tg
+.Ic macro
+.Tg "" ignored arguments
+too many
+.Tg \&badstart
+badstart
+.Tg badend\&
+badend
+.Tg "white space"
+whitespace
+.Tg sub
+.Tg double
+.Ss Subsection
+subtext
+.Tg examples
+.Sh EXAMPLES
+example
+text
+.Pp
+ENDTEST
+.Tg
diff --git a/regress/mdoc/Tg/warn.out_ascii b/regress/mdoc/Tg/warn.out_ascii
new file mode 100644
index 00000000..8dee9aed
--- /dev/null
+++ b/regress/mdoc/Tg/warn.out_ascii
@@ -0,0 +1,19 @@
+TG-WARN(1)                  General Commands Manual                 TG-WARN(1)
+
+NNAAMMEE
+     TTgg--wwaarrnn - warnings about tagging macros
+
+DDEESSCCRRIIPPTTIIOONN
+     BEGINTEST
+
+     initial text mmaaccrroo too many badstart badend whitespace
+
+   SSuubbsseeccttiioonn
+     subtext
+
+EEXXAAMMPPLLEESS
+     example text
+
+     ENDTEST
+
+OpenBSD                         March 13, 2020                         OpenBSD
diff --git a/regress/mdoc/Tg/warn.out_html b/regress/mdoc/Tg/warn.out_html
new file mode 100644
index 00000000..b4d3cf74
--- /dev/null
+++ b/regress/mdoc/Tg/warn.out_html
@@ -0,0 +1,11 @@
+<p class="Pp"><mark id="start"></mark>initial text
+    <a class="permalink" href="#macro"><code class="Ic" id="macro">macro</code></a>
+    too many badstart badend whitespace <mark id="sub"></mark></p>
+<section class="Ss">
+<h2 class="Ss" id="double"><a class="permalink" href="#double">Subsection</a></h2>
+<p class="Pp">subtext</p>
+</section>
+</section>
+<section class="Sh">
+<h1 class="Sh" id="examples"><a class="permalink" href="#examples">EXAMPLES</a></h1>
+<p class="Pp">example text</p>
diff --git a/regress/mdoc/Tg/warn.out_lint b/regress/mdoc/Tg/warn.out_lint
new file mode 100644
index 00000000..39c1f541
--- /dev/null
+++ b/regress/mdoc/Tg/warn.out_lint
@@ -0,0 +1,6 @@
+mandoc: warn.in:16:2: WARNING: skipping empty macro: Tg
+mandoc: warn.in:16:8: ERROR: skipping excess arguments: Tg ... ignored
+mandoc: warn.in:18:5: ERROR: skipping tag containing whitespace: Tg \&badstart
+mandoc: warn.in:20:11: ERROR: skipping tag containing whitespace: Tg badend\&
+mandoc: warn.in:22:10: ERROR: skipping tag containing whitespace: Tg white space
+mandoc: warn.in:34:2: WARNING: skipping empty macro: Tg
diff --git a/regress/mdoc/Tg/warn.out_markdown b/regress/mdoc/Tg/warn.out_markdown
new file mode 100644
index 00000000..87204424
--- /dev/null
+++ b/regress/mdoc/Tg/warn.out_markdown
@@ -0,0 +1,30 @@
+TG-WARN(1) - General Commands Manual
+
+# NAME
+
+**Tg-warn** - warnings about tagging macros
+
+# DESCRIPTION
+
+BEGINTEST
+
+initial
+text
+**macro**
+too many
+badstart
+badend
+whitespace
+
+## Subsection
+
+subtext
+
+# EXAMPLES
+
+example
+text
+
+ENDTEST
+
+OpenBSD - March 13, 2020
diff --git a/regress/mdoc/Tg/warn.out_tag b/regress/mdoc/Tg/warn.out_tag
new file mode 100644
index 00000000..e1fc141c
--- /dev/null
+++ b/regress/mdoc/Tg/warn.out_tag
@@ -0,0 +1,5 @@
+start 9
+macro 9
+sub 9
+double 11
+examples 14
diff --git a/regress/regress.pl b/regress/regress.pl
index 5e7927cb..3c6e64df 100755
--- a/regress/regress.pl
+++ b/regress/regress.pl
@@ -1,8 +1,8 @@
 #!/usr/bin/env perl
 #
-# $Id: regress.pl,v 1.13 2020/01/08 10:37:53 schwarze Exp $
+# $Id: regress.pl,v 1.14 2020/03/13 15:32:31 schwarze Exp $
 #
-# Copyright (c) 2017 Ingo Schwarze <schwarze@openbsd.org>
+# Copyright (c) 2017, 2018, 2019, 2020 Ingo Schwarze <schwarze@openbsd.org>
 #
 # Permission to use, copy, modify, and distribute this software for any
 # purpose with or without fee is hereby granted, provided that the above
@@ -120,16 +120,17 @@ sub fail ($$) {
 
 my $onlytest = shift // '';
 for (@ARGV) {
-	/^(all|ascii|utf8|man|html|markdown|lint|clean|verbose)$/
+	/^(all|ascii|tag|man|utf8|html|markdown|lint|clean|verbose)$/
 	    or usage "$_: invalid modifier";
 	$targets{$_} = 1;
 }
 $targets{all} = 1
-    unless $targets{ascii} || $targets{utf8} || $targets{man} ||
-      $targets{html} || $targets{markdown} ||
+    unless $targets{ascii} || $targets{tag} || $targets{man} ||
+      $targets{utf8} || $targets{html} || $targets{markdown} ||
       $targets{lint} || $targets{clean};
-$targets{ascii} = $targets{utf8} = $targets{man} = $targets{html} =
-    $targets{markdown} = $targets{lint} = 1 if $targets{all};
+$targets{ascii} = $targets{tag} = $targets{man} = $targets{utf8} =
+    $targets{html} = $targets{markdown} = $targets{lint} = 1
+    if $targets{all};
 
 
 # --- parse Makefiles --------------------------------------------------
@@ -157,7 +158,7 @@ sub parse_makefile ($%) {
 }
 
 my (@regress_tests, @utf8_tests, @lint_tests, @html_tests);
-my (%skip_ascii, %skip_man, %skip_markdown);
+my (%tag_tests, %skip_ascii, %skip_man, %skip_markdown);
 foreach my $module (qw(roff char mdoc man tbl eqn)) {
 	my %modvars;
 	parse_makefile "$module/Makefile", \%modvars;
@@ -168,36 +169,41 @@ foreach my $module (qw(roff char mdoc man tbl eqn)) {
 		delete $subvars{GOPTS};
 		delete $subvars{SKIP_GROFF};
 		delete $subvars{SKIP_GROFF_ASCII};
-		my @mandoc = ('../mandoc', split ' ', $subvars{MOPTS});
+		my @mopts = split ' ', $subvars{MOPTS};
 		delete $subvars{MOPTS};
 		my @regress_testnames;
+		if (defined $subvars{TAG_TARGETS}) {
+			$tag_tests{"$module/$subdir/$_"} = 1
+			    for split ' ', $subvars{TAG_TARGETS};
+			delete $subvars{TAG_TARGETS};
+		}
 		if (defined $subvars{REGRESS_TARGETS}) {
 			push @regress_testnames,
 			    split ' ', $subvars{REGRESS_TARGETS};
 			push @regress_tests, {
 			    NAME => "$module/$subdir/$_",
-			    MANDOC => \@mandoc,
+			    MOPTS => \@mopts,
 			} foreach @regress_testnames;
 			delete $subvars{REGRESS_TARGETS};
 		}
 		if (defined $subvars{UTF8_TARGETS}) {
 			push @utf8_tests, {
 			    NAME => "$module/$subdir/$_",
-			    MANDOC => \@mandoc,
+			    MOPTS => \@mopts,
 			} foreach split ' ', $subvars{UTF8_TARGETS};
 			delete $subvars{UTF8_TARGETS};
 		}
 		if (defined $subvars{HTML_TARGETS}) {
 			push @html_tests, {
 			    NAME => "$module/$subdir/$_",
-			    MANDOC => \@mandoc,
+			    MOPTS => \@mopts,
 			} foreach split ' ', $subvars{HTML_TARGETS};
 			delete $subvars{HTML_TARGETS};
 		}
 		if (defined $subvars{LINT_TARGETS}) {
 			push @lint_tests, {
 			    NAME => "$module/$subdir/$_",
-			    MANDOC => \@mandoc,
+			    MOPTS => \@mopts,
 			} foreach split ' ', $subvars{LINT_TARGETS};
 			delete $subvars{LINT_TARGETS};
 		}
@@ -243,22 +249,44 @@ foreach my $module (qw(roff char mdoc man tbl eqn)) {
 
 my $count_total = 0;
 my $count_ascii = 0;
+my $count_tag = 0;
 my $count_man = 0;
 my $count_rm = 0;
-if ($targets{ascii} || $targets{man}) {
-	print "Running ascii and man tests ";
+if ($targets{ascii} || $targets{tag} || $targets{man}) {
+	print "Running ascii, tag, and man tests ";
 	print "...\n" if $targets{verbose};
 }
 for my $test (@regress_tests) {
 	my $i = "$test->{NAME}.in";
 	my $o = "$test->{NAME}.mandoc_ascii";
 	my $w = "$test->{NAME}.out_ascii";
-	if ($targets{ascii} && !$skip_ascii{$test->{NAME}} &&
+	my $to = "$test->{NAME}.mandoc_tag";
+	my $tw = "$test->{NAME}.out_tag";
+	my $diff_ascii;
+	if ($targets{tag} && $tag_tests{$test->{NAME}} &&
 	    $test->{NAME} =~ /^$onlytest/) {
-		$count_ascii++;
+		$count_tag++;
 		$count_total++;
-		sysout $o, @{$test->{MANDOC}}, qw(-I os=OpenBSD -T ascii), $i
+		local $ENV{MANPAGER} = "./copyless $test->{NAME}";
+		my @cmd = (qw(../man -l), @{$test->{MOPTS}},
+		    qw(-I os=OpenBSD -T ascii), $i);
+		print "@cmd\n" if $targets{verbose};
+		system @cmd
+		    and fail $test->{NAME}, 'tag:man';
+		system @diff, $tw, $to
+		    and fail $test->{NAME}, 'tag:diff';
+		print "." unless $targets{verbose};
+		$diff_ascii = $targets{ascii};
+	} elsif ($targets{ascii} && !$skip_ascii{$test->{NAME}} &&
+	    $test->{NAME} =~ /^$onlytest/) {
+		sysout $o, '../mandoc', @{$test->{MOPTS}},
+		    qw(-I os=OpenBSD -T ascii), $i
 		    and fail $test->{NAME}, 'ascii:mandoc';
+		$diff_ascii = 1;
+	}
+	if ($diff_ascii) {
+		$count_ascii++;
+		$count_total++;
 		system @diff, $w, $o
 		    and fail $test->{NAME}, 'ascii:diff';
 		print "." unless $targets{verbose};
@@ -269,9 +297,10 @@ for my $test (@regress_tests) {
 	    $test->{NAME} =~ /^$onlytest/) {
 		$count_man++;
 		$count_total++;
-		sysout $m, @{$test->{MANDOC}}, qw(-I os=OpenBSD -T man), $i
+		sysout $m, '../mandoc', @{$test->{MOPTS}},
+		    qw(-I os=OpenBSD -T man), $i
 		    and fail $test->{NAME}, 'man:man';
-		sysout $mo, @{$test->{MANDOC}},
+		sysout $mo, '../mandoc', @{$test->{MOPTS}},
 		    qw(-man -I os=OpenBSD -T ascii -O mdoc), $m
 		    and fail $test->{NAME}, 'man:mandoc';
 		system @diff, $w, $mo
@@ -279,13 +308,13 @@ for my $test (@regress_tests) {
 		print "." unless $targets{verbose};
 	}
 	if ($targets{clean}) {
-		print "rm $o $m $mo\n" if $targets{verbose};
-		$count_rm += unlink $o, $m, $mo;
+		print "rm $o $to $m $mo\n" if $targets{verbose};
+		$count_rm += unlink $o, $to, $m, $mo;
 	}
 }
-if ($targets{ascii} || $targets{man}) {
-	print "Number of ascii and man tests:" if $targets{verbose};
-	print " $count_ascii + $count_man tests run.\n";
+if ($targets{ascii} || $targets{tag} || $targets{man}) {
+	print "Number of ascii, tag, and man tests:" if $targets{verbose};
+	print " $count_ascii + $count_tag + $count_man tests run.\n";
 }
 
 my $count_utf8 = 0;
@@ -300,7 +329,8 @@ for my $test (@utf8_tests) {
 	if ($targets{utf8} && $test->{NAME} =~ /^$onlytest/o) {
 		$count_utf8++;
 		$count_total++;
-		sysout $o, @{$test->{MANDOC}}, qw(-I os=OpenBSD -T utf8), $i
+		sysout $o, '../mandoc', @{$test->{MOPTS}},
+		    qw(-I os=OpenBSD -T utf8), $i
 		    and fail $test->{NAME}, 'utf8:mandoc';
 		system @diff, $w, $o
 		    and fail $test->{NAME}, 'utf8:diff';
@@ -328,7 +358,8 @@ for my $test (@html_tests) {
 	if ($targets{html} && $test->{NAME} =~ /^$onlytest/) {
 		$count_html++;
 		$count_total++;
-		syshtml $o, @{$test->{MANDOC}}, qw(-T html), $i
+		syshtml $o, '../mandoc', @{$test->{MOPTS}},
+		    qw(-T html), $i
 		    and fail $test->{NAME}, 'html:mandoc';
 		system @diff, $w, $o
 		    and fail $test->{NAME}, 'html:diff';
@@ -357,7 +388,7 @@ for my $test (@regress_tests) {
 	    $test->{NAME} =~ /^$onlytest/) {
 		$count_markdown++;
 		$count_total++;
-		sysout $o, @{$test->{MANDOC}},
+		sysout $o, '../mandoc', @{$test->{MOPTS}},
 		    qw(-I os=OpenBSD -T markdown), $i
 		    and fail $test->{NAME}, 'markdown:mandoc';
 		system @diff, $w, $o
@@ -386,7 +417,7 @@ for my $test (@lint_tests) {
 	if ($targets{lint} && $test->{NAME} =~ /^$onlytest/) {
 		$count_lint++;
 		$count_total++;
-		syslint $o, @{$test->{MANDOC}},
+		syslint $o, '../mandoc', @{$test->{MOPTS}},
 		    qw(-I os=OpenBSD -T lint -W all), $i
 		    and fail $test->{NAME}, 'lint:mandoc';
 		system @diff, $w, $o
@@ -418,6 +449,7 @@ if ($count_total == 1) {
 } elsif ($count_total) {
 	print "All $count_total tests OK:";
 	print " $count_ascii ascii" if $count_ascii;
+	print " $count_tag tag" if $count_tag;
 	print " $count_man man" if $count_man;
 	print " $count_utf8 utf8" if $count_utf8;
 	print " $count_html html" if $count_html;
diff --git a/regress/regress.pl.1 b/regress/regress.pl.1
index 04a56912..73db6118 100644
--- a/regress/regress.pl.1
+++ b/regress/regress.pl.1
@@ -1,6 +1,6 @@
-.\"	$Id: regress.pl.1,v 1.4 2019/03/06 15:58:11 schwarze Exp $
+.\"	$Id: regress.pl.1,v 1.5 2020/03/13 15:32:31 schwarze Exp $
 .\"
-.\" Copyright (c) 2017 Ingo Schwarze <schwarze@openbsd.org>
+.\" Copyright (c) 2017, 2019, 2020 Ingo Schwarze <schwarze@openbsd.org>
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: March 6 2019 $
+.Dd $Mdocdate: March 13 2020 $
 .Dt REGRESS.PL 1
 .Os
 .Sh NAME
@@ -78,6 +78,8 @@ output mode.
 Run subtests for
 .Fl T Cm markdown
 output mode.
+.It Cm tag
+Run subtests for automatic and manual tagging.
 .It Cm utf8
 Run subtests for
 .Fl T Cm utf8
@@ -146,15 +148,6 @@ subdirectory of the regression suite is not included.
 It uses a Makefile structure that differs vastly from the
 rest of the suite.
 .Sh BUGS
-On Oracle Solaris 11,
-.Xr diff 1
-does not support the
-.Fl a
-option.
-Delete that option from the following line in this script:
-.Pp
-.Dl my @diff = qw(diff -au);
-.Pp
 The C library function
 .Xr wcwidth 3
 is known to be buggy on Solaris, which may cause failures in the