Problem :

(a) Show whether or not a standard format for representing data, such as XML, is needed.

(b) Using an appropriate example, describe how data is organized in a data source, such as an XML document.

(c) What is an XML entity? Distinguish between a general entity and a parameter entity. Provide an example of a general entity declaration, followed by a reference to the same entity.

(d) A software company gives technical support service to its customers. A customer will request the service by filing a document. Write a DTD to define the following structure for documents of type DocReq:

1. The request consists of the customer information and the task.

2. Customer information will include the name, address and telephone number.

3. There is a track number related with each request.

4. The task will be urgent or normal, and normal is the default.