You are looking at the HTML representation of the XML format.
HTML is good for debugging, but probably is not suitable for your application.
See complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <allpages gapfrom="SIG API guide" />
  </query-continue>
  <query>
    <pages>
      <page pageid="21" ns="0" title="SIG API. Preface">
        <revisions>
          <rev xml:space="preserve">SIG is a middleware web service designed to provide IBE/OTA with a unified interface to the following functions of different GDS and local CRS.
# Fixed date shopping 
# Flex date shopping
# Flight Availability
# Fare Availability 
# Fare Rule Display
# Booking &amp; Pricing
# Ticket Issue
# Different forms of payment: CASH, CC, CASH+CC
# Booking status &amp; Repricing
# Booking Cancellation &amp; Ticket Void
# Ticket status
# Schedule Display
# Fare Display
&lt;br /&gt;
Currently SIG manages interfaces with the following systems:
# Galileo
# Sirena-Travel &amp; Sirena-2.3
# SITA Gabriel
# Biletix Distribution System (Charter Database)
&lt;br /&gt;
SIG is an execellent chance to IBE/OTA to avoid integration with many systems because it offers
# Quick new system links. As soon as organization tasks solved
# IBE/OTA developers do not need to know anything about GDS/CRS. All GDS/CRS technology concerns covered by SIG team. 
# IBE/OTA developers do not need to speak Russian to deal with Russian systems
# No extra look/book invoices even for heavy loaded B2C projects.
# Comprehensive shopping engine able to find itineraries not offered by connected GDS/CRS shopping tools
# Smart price and availability caching tools

Currently SIG is being used by the following projects: [http://www.biletix.ru biletix.ru], [http://server.portbilet.ru portbilet.ru], [http://www.tutu.ru tutu.ru], [http://www.e-ticket.ru e-ticket.ru], [http://www.aviarost.ru aviarost.ru], etc. 
These integrations work via SIG old API not available for new customers. &lt;br /&gt;
&lt;br /&gt;
Now SIG team develops new SIG API targeted to launch its basic functions at 01.10.2012.
This API described in details in other sections.</rev>
        </revisions>
      </page>
      <page pageid="23" ns="0" title="SIG API. WSDL &amp; XSD">
        <revisions>
          <rev xml:space="preserve">SIG - is SOAP server. 

Service definition file is available at [{{SigWsdlURL}} '''SIG WSDL''']

It contains the only method SIGQuerySoap which wraps the actual XML request in SIGQuery tag.

The XML requests and replies are described in '''[[media:SIG.xsd|SIG.xsd]]'''</rev>
        </revisions>
      </page>
    </pages>
  </query>
</api>