Index: en_US.ISO8859-1/books/porters-handbook/makefiles/chapter.xml
===================================================================
--- en_US.ISO8859-1/books/porters-handbook/makefiles/chapter.xml
+++ en_US.ISO8859-1/books/porters-handbook/makefiles/chapter.xml
@@ -3308,6 +3308,45 @@
       MAINTAINER variable in the <filename>Makefile</filename>.</para>
   </sect1>
 
+  <sect1 xml:id="makefile-license">
+    <title><varname>LICENSE</varname></title>
+
+    <para>Set <varname>LICENSE</varname> to let the ports infrastructure know
+      how the code is licensed. For example:</para>
+
+    <programlisting>LICENSE=	BSD3CLAUSE</programlisting>
+
+    <para>The
+      <link xlink:href="https://spdx.org/licenses/">SPDX license list</link>
+      is the canonical source for license identifiers used in the ports
+      infrastructure, subject to the following rules:</para>
+
+    <itemizedlist>
+      <listitem>
+	<para>Strip the hyphens and periods, as in the example above.</para>
+      </listitem>
+
+      <listitem>
+	<para>If the port is under multiple licenses, use a space-separated
+	  list.</para>
+      </listitem>
+
+      <listitem>
+	<para>Ports licensed with an <quote>or higher</quote> clause such as
+	  <quote>GPLv2 or higher</quote> are written as <quote>GPLv2+</quote>.
+	</para>
+      </listitem>
+    </itemizedlist>
+
+    <para>See <filename>/usr/ports/Mk/bsd.licenses.db.mk</filename> for
+      details.</para>
+
+    <para>If the port contains a file with the full text of the license, set
+      <varname>LICENSE_FILE</varname> to point to it:</para>
+
+    <programlisting>LICENSE_FILE=	${WRKSRC}/LICENSE</programlisting>
+  </sect1>
+
   <sect1 xml:id="makefile-portscout">
     <title><varname>PORTSCOUT</varname></title>