Index: chapter.xml
===================================================================
--- chapter.xml
+++ chapter.xml
@@ -552,11 +552,48 @@
 	    and
 	    <varname>NOT_FOR_ARCHS_REASON_<replaceable>ARCH</replaceable></varname>.</para>
 	</listitem>
+
+	<listitem>
+	  <para>Futher shorthands are available (cf.
+	    <link xlink:href="https://svnweb.freebsd.org/ports/head/Mk/bsd.port.mk?view=markup">bsd.port.mk</link>):</para>
+
+	  <programlisting>IGNORE_i386=		does not run on 32-bit architectures</programlisting>
+
+	  <programlisting>BROKEN_powerpc64=	not ported to powerpc64 yet</programlisting>
+	</listitem>
+      </itemizedlist>
+
+    </sect2>
+
+    <sect2 xml:id="dads-wordsize">
+      <title>Wordsize Considerations</title>
+      <itemizedlist>
+	<listitem>
+	  <para>Some ports are affected by features particular to some
+	    of &os;'s supported architectures (see
+	    <literal>TARGETS</literal> in
+	    <link xlink:href="https://svnweb.freebsd.org/base/head/Makefile">base/head/Makefile</link>).
+	    </para>
+
+	  <para>Here are some examples of usage:</para>
+
+	  <programlisting># modify CXXFLAGS on 32-bit archs
+.if ${ARCH} == armv6 || ${ARCH} == armv7 || ${ARCH} == i386 || ${ARCH} == mips || ${ARCH} == powerpc || ${ARCH} == powerpcspe
+CXXFLAGS+= ...
+.endif</programlisting>
+
+	  <programlisting># modify LDFLAGS on 64-bit archs
+.if ${ARCH} == aarch64 || ${ARCH} == amd64 || ${ARCH} == mips64 || ${ARCH} == powerpc64 || ${ARCH} == sparc64 || ${ARCH} == riscv
+LDFLAGS+= ...
+.endif</programlisting>
+
+	</listitem>
       </itemizedlist>
 
     </sect2>
 
     <sect2 xml:id="dads-arch-i386">
+      <title>i386-Specific Considerations</title>
       <itemizedlist>
 	<listitem>
 	  <para>If a port fetches i386 binaries and installs them,