diff --git a/doc/mkvmerge-gui.html b/doc/mkvmerge-gui.html
index 845f5d696..f1e2d2800 100644
--- a/doc/mkvmerge-gui.html
+++ b/doc/mkvmerge-gui.html
@@ -54,6 +54,9 @@
               track
             </a>
           </li>
+          <li>
+            <a href="mkvmerge-gui.html#attachments">Attachments</a>
+          </li>
           <li>
             <a href="mkvmerge-gui.html#globaloptions">Global options</a>
           </li>
@@ -223,7 +226,10 @@
 
   <p>Once the user selects an input <i>file</i> in the upper list box
   the second list box will contains all <i>tracks</i> that can be read
-  from this <i>file</i>. For each of these tracks the user can select
+  from this <i>file</i>. Each track is ENabled by default and will be
+  muxed into the resulting file. However, you can change that by simply
+  clicking on the checkbox right in front of the track's name in the
+  second list box. For each of these tracks the user can select
   track specific options with the input boxes and check boxes below the
   track listing. These options will be described in the following
   sections.</p>
@@ -321,8 +327,111 @@
   </ul>
   </p>
 
+  <h3><a name="attachments">Attachments</a></h3>
+
+  <p>Matroska files can also contain other files, called
+  attachments. This works basically just like with your favourite email
+  program. The idea is to provide additional information about the
+  file. Some examples could be cover photos for a CD rip, additional
+  background information in text form about the movie or even some
+  compressed fonts for the subtitles.</p>
+
+  <p>Every attachment needs two things: the file name (obviously) and
+  the MIME type that should be associated with the file. The usage is
+  very easy and similar to adding files on the <i>input</i> tab.</p>
+
+  <p>On the second tab of the GUI, the <i>attachment</i> tab, you can
+  add a file with the <i>+</i> button and remove the selected attachment
+  with the <i>-</i> button. Once an attachment has been selected the
+  other controls on this tab will be available. You do have to select a
+  MIME type for each attachment, but the description is optional -
+  although it is a good idea to always provide a description. This makes
+  it easier for others to identify what you've attached to this Matroska
+  file.</p>
+
+  <p>The last option, <code>attachment style</code>, is only evaluated
+  when you also split the output into several files. (Splitting in
+  general is explained in the following section.) If the option <code>To
+  all files</code> is selected then the current file will be attached to
+  all output files created. If the option <code>Only to the first</code>
+  is selected then the file is only attached to the very first output
+  file created.</p>
+
   <h3><a name="globaloptions">Global options</a></h3>
 
+  <p>The third tab, <i>Global</i>, is packed full of options that apply
+  to the complete file and not just to one or more tracks.</p>
+
+  <h4><a name="global_title">File/segment title</a></h4>
+
+  <p><code>File/segment title:</code> This title is used for the
+  actual movie title, e.g. 'Vanilla Skies'.</p>
+
+  <h4><a name="global_split">Automatic splitting and file linking</a></h4>
+
+  <p>The <code>Split</code> section handles how the output file is split
+  into several smaller files. If no splitting is selected then only one
+  big file is generated. If splitting is activated then you can tell
+  <i>mkvmerge</i> to start a new output file after either a specific
+  amount of data has been written to the current file or after a
+  specific amount of time has accumulated. The formats accepted are:
+  <br>
+  <ul>
+    <li>For the size: A number optionally followed by the letter 'K',
+    'M' or 'G' indicating kilobytes (1024 bytes), megabytes (1024 * 1024
+    bytes) or gigabytes (1024 * 1024 * 1024 bytes). Examples: '700M' or
+    '100000K'.</li>
+    <li>For the time: The format is either <code>HH:MM:SS</code> or a
+    number followed by the letter 's' indicating a number of
+    seconds. Examples: '01:20:00' (split after 1 hour, 20 minutes) or
+    '1800s' (split after 1800 seconds = 30 minutes).</li>
+  </ul></p>
+
+  <p><code>Don't link:</code> This option controls how <i>mkvmerge</i>
+  will handle splitting. A little explanation about this feature:</p>
+
+  <p>Matroska supports file linking which simply says that a specific
+  file is the predecessor or successor of the current file. To be
+  precise, it's not really the files that are linked but the Matroska
+  segments. As most files will probably only contain one Matroska
+  segment I simply say 'file linking' although 'segment linking' would
+  be more appropriate.</p>
+
+  <p>Each segment is identified by a unique 128 bit wide segment
+  UID. This UID is automatically generated by <i>mkvmerge</i>. The
+  linking is done primarily via putting the segment UIDs of the
+  previous/next file into the segment header information. <i>mkvinfo</i>
+  prints these UIDs if it finds them.</p>
+
+  <p>If a file is split into several smaller ones and linking is used
+  then the timecodes will not start at 0 again but will continue where
+  the last file has left off. This way the absolute time is kept even if
+  the previous files are not available (e.g. when streaming). If no
+  linking is used then the timecodes should start at 0 for each file. By
+  default <i>mkvmerge</i> uses file linking. If you don't want that you
+  can turn it off by enabling this <code>Don't link</code> checkbox.</p>
+
+  <h4><a name="global_link">Manual file/segment linking</a></h4>
+
+  <p>Regardless of whether splitting is active or not the user can tell
+  <i>mkvmerge</i> to link the produced files to specific UIDs. This is
+  done by entering a valid segment UID into the two input boxes,
+  <code>Previous segment UID</code> and <code>Next segment UID</code>.
+  These options accept a segment UID in the format that <i>mkvinfo</i>
+  outputs: 16 hexadecimal numbers between 0x00 and 0xff prefixed with
+  '0x' each and separated with spaces, e.g. <code>0x41 0xda 0x73 0x66
+  0xd9 0xcf 0xb2 0x1e 0xae 0x78 0xeb 0xb4 0x5e 0xca 0xb3
+  0x93</code>. Alternatively a shorter form can be used: 16 hexadecimal
+  numbers between 0x00 and 0xff without the '0x' prefixes and without
+  the spaces, e.g.  <code>41da7366d9cfb21eae78ebb45ecab393</code>.</p>
+
+  <p>If splitting is used then the first file is linked to the UID given
+  in the <code>Previous segment UID</code> input box, and the last file
+  is linked to the UID given in the <code>Next segment UID</code> input
+  box. If splitting is not used then the one output file will be linked
+  to both of the two UIDs.</p>
+   
+
   <h3><a name="doit">Starting the merge process</a></h3>
 
   <h3><a name="saveload">Saving and loading muxing settings</a></h3>