Index: /trunk/doc/manual/en_US/user_Storage.xml
===================================================================
--- /trunk/doc/manual/en_US/user_Storage.xml	(revision 55152)
+++ /trunk/doc/manual/en_US/user_Storage.xml	(revision 55153)
@@ -36,21 +36,22 @@
 
   <sect1 id="harddiskcontrollers">
-    <title>Hard disk controllers: IDE, SATA (AHCI), SCSI, SAS</title>
+    <title>Hard disk controllers: IDE, SATA (AHCI), SCSI, SAS, USB MSC</title>
 
     <para>In a real PC, hard disks and CD/DVD drives are connected to a device
     called hard disk controller which drives hard disk operation and data
-    transfers. VirtualBox can emulate the four most common types of hard disk
-    controllers typically found in today's PCs: IDE, SATA (AHCI), SCSI and
-    SAS.<footnote>
+    transfers. VirtualBox can emulate the five most common types of hard disk
+    controllers typically found in today's PCs: IDE, SATA (AHCI), SCSI,
+    SAS and USB based mass storage devices.<footnote>
         <para>SATA support was added with VirtualBox 1.6; experimental SCSI
         support was added with 2.1 and fully implemented with 2.2. Generally,
         storage attachments were made much more flexible with VirtualBox 3.1;
         see below. Support for the LSI Logic SAS controller was added with
-        VirtualBox 3.2.</para>
+        VirtualBox 3.2; USB mass storage devices are supported since
+        VirtualBox 5.0.</para>
       </footnote><itemizedlist>
         <listitem>
           <para><emphasis role="bold">IDE (ATA)</emphasis> controllers are a
           backwards compatible yet very advanced extension of the disk
-	  controller in the IBM PC/AT (1984). Initially, this interface
+          controller in the IBM PC/AT (1984). Initially, this interface
           worked only with hard disks, but was later extended to also support
           CD-ROM drives and other types of removable media. In physical PCs,
@@ -59,5 +60,5 @@
           traditionally been called "master" and "slave". Typical PCs had
           two connectors for such cables; as a result, support for up to four
-	  IDE devices was most common.</para>
+          IDE devices was most common.</para>
 
           <para>In VirtualBox, each virtual machine may have one IDE
@@ -190,4 +191,23 @@
           </warning>
         </listitem>
+
+        <listitem>
+          <para>The <emphasis role="bold">USB mass storage device class</emphasis>
+          is a standard to connect external storage devices like hard or flash
+          drives to a host through USB. All major operating systems support
+          these devices for a long time and ship with a generic driver which
+          makes third party drivers unnecessary.
+          The virtual USB storage controller offered by VirtualBox works
+          different than the other storage controller types. Unlike the
+          controllers which appear as a single PCI device to the guest with
+          multiple disks attached to it, the USB based storage controller does
+          not appear directly in the guest. Each disk attached to the controller
+          appears as a different USB device to the guest.</para>
+
+          <warning>
+            <para>As of version 5.0 VirtualBox does not support booting from
+            drives attached via USB.</para>
+          </warning>
+        </listitem>
       </itemizedlist></para>
 
@@ -212,4 +232,9 @@
         <listitem>
           <para>eight slots attached to the SAS controller, if enabled and
+          supported by the guest operating system.</para>
+        </listitem>
+
+        <listitem>
+          <para>eight slots attached to the virtual USB controller, if enabled and
           supported by the guest operating system.</para>
         </listitem>
Index: /trunk/doc/manual/en_US/user_VBoxManage.xml
===================================================================
--- /trunk/doc/manual/en_US/user_VBoxManage.xml	(revision 55152)
+++ /trunk/doc/manual/en_US/user_VBoxManage.xml	(revision 55153)
@@ -2173,5 +2173,5 @@
                             [--add &lt;ide/sata/scsi/floppy&gt;]
                             [--controller &lt;LsiLogic|LSILogicSAS|BusLogic|
-                                          IntelAhci|PIIX3|PIIX4|ICH6|I82078&gt;]
+                                          IntelAhci|PIIX3|PIIX4|ICH6|I82078|usb&gt;]
                             [--sataportcount &lt;1-30&gt;]
                             [--hostiocache on|off]