man: explicitly distinguish "implicit dependencies" and "default dependencies"

Fixes: #6793

1 files changed, 32 insertions, 15 deletions

diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml
index 32399ef993..69000aab31 100644
--- a/man/systemd.unit.xml
+++ b/man/systemd.unit.xml
@@ -268,25 +268,42 @@
   </refsect1>
 
   <refsect1>
-    <title>Automatic Dependencies</title>
-
-    <para>A number of unit dependencies are automatically established,
-    depending on unit configuration. On top of that, for units with
-    <varname>DefaultDependencies=yes</varname> (the default) a couple
-    of additional dependencies are added. The precise effect of
-    <varname>DefaultDependencies=yes</varname> depends on the unit
-    type (see below).</para>
-
-    <para>If <varname>DefaultDependencies=yes</varname> is set, units
-    that are referenced by other units of type
-    <filename>.target</filename> via a <varname>Wants=</varname> or
-    <varname>Requires=</varname> dependency might automatically gain
-    an <varname>Before=</varname> dependency too. See
-    <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+    <title>Implicit Dependencies</title>
+
+    <para>A number of unit dependencies are implicitly established,
+    depending on unit type and unit configuration. These implicit
+    dependencies can make unit configuration file cleaner. For the
+    implicit dependencies in each unit type, please refer to
+    section "Implicit Dependencies" in respective man pages.</para>
+
+    <para>For example, service units with <varname>Type=dbus</varname>
+    automatically acquire dependencies of type <varname>Requires=</varname>
+    and <varname>After=</varname> on <filename>dbus.socket</filename>. See
+    <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
     for details.</para>
   </refsect1>
 
   <refsect1>
+    <title>Default Dependencies</title>
+
+    <para>Default dependencies are similar to implicit dependencies,
+    but can be turned on and off by setting
+    <varname>DefaultDependencies=</varname> to <varname>yes</varname>
+    (the default) and <varname>no</varname>, while implicit dependencies
+    are always in effect. See section "Default Dependencies" in respective
+    man pages for the effect of enabling
+    <varname>DefaultDependencies=</varname> in each unit types.</para>
+
+    <para>For example, target units will complement all configured
+    dependencies of type type <varname>Wants=</varname> or
+    <varname>Requires=</varname> with dependencies of type
+    <varname>After=</varname>. See
+    <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+    for details. Note that this behavior can be turned off by setting
+    <varname>DefaultDependencies=no</varname>.</para>
+  </refsect1>
+
+  <refsect1>
     <title>Unit File Load Path</title>
 
     <para>Unit files are loaded from a set of paths determined during