diff --git a/.gitmodules b/.gitmodules
index 717fb5d57..97e7edb2d 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "share/git/kmkf"]
 	path = share/git/kmkf
 	url = https://github.com/katef/kmkf
+[submodule "share/git/mdb"]
+	path = share/git/mdb
+	url = https://github.com/katef/minidocbook
diff --git a/share/dtd/ent-arg.dtd b/share/dtd/ent-arg.dtd
deleted file mode 100644
index d794f3600..000000000
--- a/share/dtd/ent-arg.dtd
+++ /dev/null
@@ -1,43 +0,0 @@
-<!-- $Id$ -->
-
-<!ENTITY dot.lit        "<literal>.</literal>">
-<!ENTITY comma.lit      "<literal>,</literal>">
-<!ENTITY colon.lit      "<literal>:</literal>">
-<!ENTITY semi.lit       "<literal>;</literal>">
-<!ENTITY equal.lit      "<literal>=</literal>">
-<!ENTITY hyphen.lit     "<literal>-</literal>">
-<!ENTITY plus.lit       "<literal>+</literal>">
-<!ENTITY open.lit       "<literal>(</literal>">
-<!ENTITY close.lit      "<literal>)</literal>">
-<!ENTITY open-s.lit     "<literal>[</literal>">
-<!ENTITY close-s.lit    "<literal>]</literal>">
-<!ENTITY ellipsis.lit   "<arg choice='plain' rep='repeat'/>">
-
-<!ENTITY in-file.arg    "<replaceable>input-file</replaceable>">
-<!ENTITY out-file.arg   "<replaceable>output-file</replaceable>">
-<!ENTITY temp-file.arg  "<replaceable>template-file</replaceable>">
-<!ENTITY dump-file.arg  "<replaceable>dump-file</replaceable>">
-<!ENTITY spec-file.arg  "<replaceable>spec-file</replaceable>">
-<!ENTITY port-table.arg "<replaceable>port-table</replaceable>">
-
-<!ENTITY predicate.arg  "<replaceable>predicate</replaceable>">
-<!ENTITY options.arg    "<replaceable>options</replaceable>">
-<!ENTITY tokens.arg     "<replaceable>tokens</replaceable>">
-<!ENTITY letter.arg     "<replaceable>letter</replaceable>">
-<!ENTITY suffix.arg     "<replaceable>suffix</replaceable>">
-<!ENTITY switch.arg     "<replaceable>switch</replaceable>">
-<!ENTITY macro.arg      "<replaceable>macro</replaceable>">
-<!ENTITY ident.arg      "<replaceable>ident</replaceable>">
-<!ENTITY name.arg       "<replaceable>name</replaceable>">
-<!ENTITY file.arg       "<replaceable>file</replaceable>">
-<!ENTITY text.arg       "<replaceable>text</replaceable>">
-<!ENTITY lang.arg       "<replaceable>lang</replaceable>">
-<!ENTITY str.arg        "<replaceable>str</replaceable>">
-<!ENTITY num.arg        "<replaceable>num</replaceable>">
-<!ENTITY env.arg        "<replaceable>env</replaceable>">
-<!ENTITY dir.arg        "<replaceable>dir</replaceable>">
-<!ENTITY opt.arg        "<replaceable>opt</replaceable>">
-
-<!-- TODO: I'm unsure about how best to present this. I think it means a term is optional in a grammar -->
-<!ENTITY opt.bnf "?">
-
diff --git a/share/dtd/ent-arg.dtd b/share/dtd/ent-arg.dtd
new file mode 120000
index 000000000..702de1d26
--- /dev/null
+++ b/share/dtd/ent-arg.dtd
@@ -0,0 +1 @@
+../../share/git/mdb/share/dtd/ent-arg.dtd
\ No newline at end of file
diff --git a/share/dtd/ent-misc.dtd b/share/dtd/ent-misc.dtd
deleted file mode 100644
index 132daa29f..000000000
--- a/share/dtd/ent-misc.dtd
+++ /dev/null
@@ -1,23 +0,0 @@
-<!-- $Id: ent-misc.dtd 3943 2015-02-24 11:27:49Z kate $ -->
-
-<!-- TODO: all in hex -->
-<!ENTITY nbsp   "&#160;">
-<!ENTITY hellip "&#133;">
-<!ENTITY ndash  "&#8211;">
-<!ENTITY mdash  "&#8212;">
-<!ENTITY larr   "&#8592;">
-<!ENTITY rarr   "&#8594;">
-<!ENTITY harr   "&#x2194;">
-<!ENTITY cross  "&#x2717;">
-<!ENTITY check  "&#x2713;">
-<!ENTITY mnplus "&#x2213;">
-<!ENTITY ldquo  "&#x201C;">
-<!ENTITY rdquo  "&#x201D;">
-<!ENTITY times  "&#215;">
-<!ENTITY reg    "&#174;">
-<!ENTITY le     "&#8804;">
-<!ENTITY ge     "&#8805;">
-
-<!ENTITY ccedil "&#231;">
-<!ENTITY egrave "&#232;">
-
diff --git a/share/dtd/ent-misc.dtd b/share/dtd/ent-misc.dtd
new file mode 120000
index 000000000..b82bed4fc
--- /dev/null
+++ b/share/dtd/ent-misc.dtd
@@ -0,0 +1 @@
+../../share/git/mdb/share/dtd/ent-misc.dtd
\ No newline at end of file
diff --git a/share/dtd/ent-ref.dtd b/share/dtd/ent-ref.dtd
index 4922f1d9d..7244b1fc2 100644
--- a/share/dtd/ent-ref.dtd
+++ b/share/dtd/ent-ref.dtd
@@ -63,6 +63,8 @@
 <!ENTITY fsm_concat.3      "<citerefentry><refentrytitle>fsm_concat</refentrytitle> %vol.3;</citerefentry>">
 <!ENTITY fsm_example.3     "<citerefentry><refentrytitle>fsm_example</refentrytitle> %vol.3;</citerefentry>">
 
+<!ENTITY fsm_countstates.3 "<citerefentry><refentrytitle>fsm_countstates</refentrytitle> %vol.3;</citerefentry>">
+
 <!ENTITY fsm_print.3    "<citerefentry><refentrytitle>fsm_print</refentrytitle> %vol.3;</citerefentry>">
 
 <!ENTITY re_comp.3re    "<citerefentry><refentrytitle>re_comp</refentrytitle> %vol.3re;</citerefentry>">
diff --git a/share/git/mdb b/share/git/mdb
new file mode 160000
index 000000000..e200edd0a
--- /dev/null
+++ b/share/git/mdb
@@ -0,0 +1 @@
+Subproject commit e200edd0a5c33ab596d0a0f59872cd7fe931d945