diff --git a/man/bootctl.xml b/man/bootctl.xml
index 816b6180874..3c9e604f7cc 100644
--- a/man/bootctl.xml
+++ b/man/bootctl.xml
@@ -114,7 +114,7 @@
         <term><option>list</option></term>
 
         <listitem><para>Shows all available boot loader entries implementing the <ulink
-        url="https://github.com/systemd/systemd/blob/master/docs/BOOT_LOADER_SPECIFICATION.md">Boot Loader
+        url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader
         Specification</ulink>, as well as any other entries discovered or automatically generated by the boot
         loader.</para></listitem>
       </varlistentry>
@@ -147,7 +147,7 @@
     <title>See Also</title>
     <para>
       <citerefentry><refentrytitle>systemd-boot</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
-      <ulink url="https://github.com/systemd/systemd/blob/master/docs/BOOT_LOADER_SPECIFICATION.md">Boot Loader Specification</ulink>,
+      <ulink url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink>,
       <ulink url="https://www.freedesktop.org/wiki/Software/systemd/BootLoaderInterface">Boot Loader Interface</ulink>
     </para>
   </refsect1>
diff --git a/man/kernel-install.xml b/man/kernel-install.xml
index 522d5fb54d4..884b25da9b4 100644
--- a/man/kernel-install.xml
+++ b/man/kernel-install.xml
@@ -165,7 +165,7 @@
     <para>
       <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
-      <ulink url="https://github.com/systemd/systemd/blob/master/docs/BOOT_LOADER_SPECIFICATION.md">Boot Loader Specification</ulink>
+      <ulink url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink>
     </para>
   </refsect1>
 
diff --git a/man/systemd-boot.xml b/man/systemd-boot.xml
index 6abed7693a8..c3b34e54c93 100644
--- a/man/systemd-boot.xml
+++ b/man/systemd-boot.xml
@@ -38,13 +38,13 @@
 
     <itemizedlist>
       <listitem><para>Boot entries defined with <ulink
-      url="https://github.com/systemd/systemd/blob/master/docs/BOOT_LOADER_SPECIFICATION.md">Boot Loader
+      url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader
       Specification</ulink> description files located in <filename>/loader/entries/</filename> on the ESP. These
       usually describe Linux kernel images with associated initrd images, but alternatively may also describe
       arbitrary other EFI executables.</para></listitem>
 
       <listitem><para>Unified kernel images following the <ulink
-      url="https://github.com/systemd/systemd/blob/master/docs/BOOT_LOADER_SPECIFICATION.md">Boot Loader
+      url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader
       Specification</ulink>, as executable EFI binaries in <filename>/EFI/Linux/</filename> on the ESP.
       </para></listitem>
 
@@ -231,9 +231,9 @@
     <filename>/loader/loader.conf</filename> on the ESP (in combination with data read from EFI variables). See
     <citerefentry><refentrytitle>loader.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Boot entry
     description files following the <ulink
-    url="https://github.com/systemd/systemd/blob/master/docs/BOOT_LOADER_SPECIFICATION.md">Boot Loader
+    url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader
     Specification</ulink> are read from <filename>/loader/entries/</filename> on the ESP. Unified kernel boot entries
-    following the <ulink url="https://github.com/systemd/systemd/blob/master/docs/BOOT_LOADER_SPECIFICATION.md">Boot
+    following the <ulink url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot
     Loader Specification</ulink> are read from <filename>/EFI/Linux/</filename> on the ESP.</para>
   </refsect1>
 
@@ -242,7 +242,7 @@
     <para>
       <citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>loader.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
-      <ulink url="https://github.com/systemd/systemd/blob/master/docs/BOOT_LOADER_SPECIFICATION.md">Boot Loader Specification</ulink>,
+      <ulink url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink>,
       <ulink url="https://www.freedesktop.org/wiki/Software/systemd/BootLoaderInterface">Boot Loader Interface</ulink>
     </para>
   </refsect1>
diff --git a/man/systemd-portabled.service.xml b/man/systemd-portabled.service.xml
index 06e9ce7837d..8c5e4cc5a1a 100644
--- a/man/systemd-portabled.service.xml
+++ b/man/systemd-portabled.service.xml
@@ -36,7 +36,7 @@
     <para>Most of <command>systemd-portabled</command>'s functionality is accessible through the
     <citerefentry><refentrytitle>portablectl</refentrytitle><manvolnum>1</manvolnum></citerefentry> command.</para>
 
-    <para>See the <ulink url="https://github.com/systemd/systemd/blob/master/docs/PORTABLE_SERVICES.md">Portable
+    <para>See the <ulink url="https://systemd.io/PORTABLE_SERVICES">Portable
     Services Documentation</ulink> for details about the concepts this service implements.</para>
   </refsect1>
 
diff --git a/man/systemd-sysusers.xml b/man/systemd-sysusers.xml
index 7da2c55d273..6c9b921f05a 100644
--- a/man/systemd-sysusers.xml
+++ b/man/systemd-sysusers.xml
@@ -130,7 +130,8 @@
     <title>See Also</title>
     <para>
       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
-      <citerefentry><refentrytitle>sysusers.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+      <citerefentry><refentrytitle>sysusers.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+      <ulink url="https://systemd.io/UIDS-GIDS">Users, Groups, UIDs and GIDs on systemd systems</ulink>
     </para>
   </refsect1>
 
diff --git a/man/systemd.xml b/man/systemd.xml
index f12956a8a53..e8f022f5597 100644
--- a/man/systemd.xml
+++ b/man/systemd.xml
@@ -882,6 +882,9 @@
         for more information.</para></listitem>
       </varlistentry>
     </variablelist>
+
+    <para>For further environment variables understood by systemd and its various components, see <ulink
+    url="https://systemd.io/ENVIRONMENT">Known Environment Variables</ulink>.</para>
   </refsect1>
 
   <refsect1>