A key principle in VNS is that a content entity can be fetched using several different communication protocols such as http, FTP and SOAP. For instance, the FTP protocol can be used to fetch xmlentity, htmlentity, textentity and wordentity and vice versa an htmlentity can be fetched using http, FTP, FILE, SCRIPT et c. This provides you with great flexibility to design your application and its interfacing with different information sources.

Fetching content entities involves a number of steps:

• Specification of the source
• Selection of method for fetching content
• Controlling the XML markup
• Validation against a schema
• Access and security constraints
• Error handling
• Timeout
• Limiting the received result
• Specifying format for inclusion in your content entity.

Note that the fetching attributes, unlike the transformation attributes, are independ of the order in which you write them in your content entity element.