Modernize the question relating to whether sources need to be installed.

Reviewed by:	dougb
Approved by:	wblock

en_US.ISO8859-1/books/faq/book.sgml

@@ -1813,35 +1813,17 @@
 
       <qandaentry>
 	<question id="need-complete-sources">
-	  <para>Do I need to install the complete sources?</para>
+	  <para>Do I need to install the source?</para>
 	</question>
 
 	<answer>
-	  <para>In general, no.  However, we would strongly recommend
-	    that you install, at a minimum, the <literal>base</literal>
-	    source kit, which includes several of the files mentioned
-	    here, and the <literal>sys</literal> (kernel) source kit,
-	    which includes sources for the kernel.  There is nothing in
-	    the system which requires the presence of the sources to
-	    operate, however, except for the kernel-configuration
-	    program &man.config.8;.  With the exception of the kernel
-	    sources, our build structure is set up so that you can
-	    read-only mount the sources from elsewhere via NFS and still
-	    be able to make new binaries (due to the kernel-source
-	    restriction, we recommend that you not mount this on
-	    <filename class="directory">/usr/src</filename> directly, but
-	    rather in some other location with appropriate symbolic
-	    links to duplicate the top-level structure of the source
-	    tree).</para>
-
-	  <para>Having the sources on-line and knowing how to build a
-	    system with them will make it much easier for you to upgrade
-	    to future releases of &os;.</para>
-
-	  <para>To actually select a subset of the sources, use the
-	    <guimenuitem>Custom</guimenuitem> menu item when you are in
-	    the <guimenuitem>Distributions</guimenuitem> menu of the
-	    system installation tool.</para>
+	  <para>In general, no.  There is nothing in the base
+	    system which requires the presence of the source to
+	    operate.  Some ports, like <filename
+	      role="package">sysutils/lsof</filename>, will not build
+	    unless the source is installed.  In particular, if the
+	    port builds a kernel module or directly operates on kernel
+	    structures, the source must be installed.</para>
 	</answer>
       </qandaentry>