  <h1 align="center">Alternative Language Links</h1>
  
<ul class="toc">
  <li><a href="#intro">Introduction</a></li>
  <li><a href="#block">The Altlang Block</a></li>
  <li><a href="#uses">Uses of Altlangs</a></li>
  <li><a href="#theory">Altlang Theory - The Worldlinkerator and the Importance 
    of Reciprocality</a></li>
  <li><a href="#seealso">See Also</a></li>
</ul>
<h3><a name="intro"></a>Introduction</h3>
<p> Alternative language links, also known as 'altlangs', are internal devices 
    used to show the relationship between two categories in different languages. 
  </p>
  <p>As you may be aware, DMOZ has a top-level category called <a href="http://dmoz.org/World/">World/</a> 
    which houses links to sites written in non-English languages. Where sensible, 
    World/&lt;language&gt; categories are organised in a similar fashion to the English-side 
    of the directory. This being especially true of the top-level categories. 
    One of the reasons for this arrangement is that it facilities the linking 
    together of categories with an identical scope. </p>
  <h3><a name="block"></a>The Altlang Block</h3>
  <p>Collectively, all the altlangs in a category are said to be in the category's 
    "altlang block". This is because, on both the edit-side view of a category 
    and the public-side view of a category, the altlangs are arranged in a block 
    aligned to the right-hand side of the page.</p>
  <p> On the public-side the block is located underneath the text: "This category 
    in other languages" (or this text in the language of the category in which 
    it appears. For example, inside <a href="http://dmoz.org/World/Italiano/">World/Italiano</a> 
    the text reads "Questa categoria in altre lingue"). </p>
  <p>In the altlang block the link titles are in the language of the category 
    in which they reside. For example, <a href="http://dmoz.org/Recreation/">Recreation/</a> 
    links to its <a href="http://dmoz.org/World/Espa%f1ol/Recreaci%f3n/">Spanish 
    equivalent</a> with the word 'Spanish', but the Spanish equivalent of Recreation/ 
    , <a href="http://dmoz.org/World/Espa%f1ol/Recreaci%f3n/">World/Espaol/Recreacin</a>, 
    has a reciprocal link entitled 'Ingls' (the Spanish word for 'English'.)</p>
  <h3><a name="uses"></a>Uses of Altlangs</h3>
  <p>Multi-lingual users typically use altlangs so they can browse, for example, 
    sites written in English about health, and sites written in Russian about 
    health. If used properly, altlangs enable these users to traverse between 
    different languages seamlessly.</p>
  <p> Editors can use altlangs to forward mis-submitted sites to the correct category. 
    To aid them in this process, the categories specified in the altlang block 
    appear as choices in the 'Move to another category' box on the <a href="/ddp/06000/">Edit 
    URL</a> screen.</p>
  <p> For example, if an editor of a category for Madagascan chickens received 
    a site about his favourite animal that was written in Spanish, he could consult 
    the drop-down list box on his Edit URL screen, and, if an equivalent category 
    in <a href="http://dmoz.org/World/Espa%f1ol/">World/Espaol</a> was present, 
    he could simply select that category and forward the site there. Alternatively, 
    if there was no entry for Spanish, he could look at the altlang block in the 
    parent category for an altlang to World/Espaol there. If one existed, he 
    could forward the site to that category; otherwise he would repeat the process. 
  </p>
  <h3><a name="theory"></a>Altlang Theory - The Worldlinkerator and the Importance 
    of Reciprocality</h3>
  <p>Altlangs should always be reciprocal. That is to say, if category A altlang 
    links to category B, category B should also altlang link back to A. Not only 
    does this process enable the seamless traversal of categories in different 
    languages which was mentioned earlier, it also helps make the network of altlang 
    links potentially more comprehensive. </p>
  <p>The latter point deserves further explanation. A script has been written 
    called the <a href="http://dmoz.org/Bookmarks/R/rpfuller/ODP/Tools/Worldlinkerator/">Worldlinkerator</a> 
    which, given a starting category, crawls altlang'd categories attempting to 
    produce a list of all categories that are equivalent but in different languages. 
    It then allows the user to update the relevant altlang blocks for the categories 
    crawled so as to increase their comprehensiveness. </p>
  <p>For example, consider <a href="http://dmoz.org/Arts/">Arts/</a> . The Arts/ 
    category in German is <a href="http://dmoz.org/World/Deutsch/Kultur/">World/Deutsch/Kultur</a> 
    . Imagine that the English category links to the German category, and nowhere 
    else. Then, imagine that the German category links to the Spanish Arts/ category 
    ( <a href="http://dmoz.org/World/Espa%f1ol/Artes/">World/Espaol/Artes</a> 
    ). In this scenario, the altlang block for the English category is incomplete 
    -- it doesn't include Spanish. By running the Worldlinkerator on the English 
    category, the user would be informed of the existence of the Spanish category 
    and thus be able to link to it from Arts/ . This is because the tool would 
    find the link from Arts/ to World/Deutsch/Kultur (confirming that the latter 
    is equivalent to the former) and then would follow the link from World/Deutsch/Kultur/ 
    to World/Espaol/Artes (confirming that the latter is equivalent to the former). 
    Given the equivalency between the German and Spanish categories, it follows 
    that the Spanish category must also be equivalent to the English category. 
  </p>
  <p>As you may have noticed, for this process to be useful it is vital existing 
    altlangs being correct. If they are not, a user running the Worldlinkerator 
    -- even if they are doing so with due care -- is likely to exacerbate the 
    situation. Returning to our previous example, if Arts/ altlang'd to the French 
    equivalent of <a href="http://dmoz.org/Computers/">Computers/</a> ( <a href="http://dmoz.org/World/Fran%e7ais/Informatique/">World/Franais/Informatique</a> 
    ) then the program would assume that all of the altlangs from World/Franais/Informatique 
    pointed to categories equivalent to Arts/...</p>
  
<p> In an attempt to reduce the number of asymmetric altlangs, editor <a href="http://dmoz.org/editors/profile.cgi?editor=sfromis">sfromis</a> 
  periodically generates a report detailing the discrepancies -- <a href="http://home1.inet.tele.dk/sfromis/BabelTower.html">the 
  ODP Tower of Babel </a>.</p>
<h3><a name="seealso"></a>See Also:</h3>
<ul>
  <li><a href="/ddp/01001/">@links and Related Categories</a> - Other types of internal 
    links, generally used for linking together categories in the same language.</li>
  <li> <a href="http://dmoz.org/newsletter/2001Dec/altlanglinking.html">Alternative 
    Language Linking: Please Take Care</a> - Newsletter article written by editor 
    <a href="http://dmoz.org/editors/profile.cgi?editor=jorisdelft">jorisdelft</a>. 
  </li>
</ul>
