The request contains, optionally, a timestamp (tag timestamp, contained into tag query) which returns only the coutries modified after that day.
The (type) attribute has to be set to countries.
<?xml version="1.0" encoding="UTF-8"?>
<envelope>
<header>
<actor>test</actor>
<user>test</user>
<password>test</password>
<version>1.6.3</version>
<timestamp>20190423170100</timestamp>
</header>
<query type="countries" product="hotel">
<timestamp>20190423170100</timestamp>
</query>
</envelope>
The response message contains in its response, tag the list of all the details of the country in the form