Microsoft Word Applied xml a toolkit for Programmers Wiley doc

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Okay, you’ve waited patiently enough. Let’s get our hands dirty and start exploring the 
nitty-gritty details. We begin by going over the XML document syntax.
XML Document Syntax
As we mentioned earlier, an XML document is made of content (character data) 
encapsulated in markup. There are seven types of markup that can be used in an XML 
document:
•
Element start and end tags
•
Attributes
•
Comments
•
Entity references
•
Processing instructions
•
Character data sections (CDATA)
•
Document type declarations 
In the next few sections, we go over each type of markup with examples of how to use 
them.
Element Start and End Tags
Elements are the most basic building blocks of XML documents. They can be used to 
both contain information and define structure. An element starts out with a starting tag 
and ends with a corresponding ending tag.
The start tag consists of a single word (no spaces allowed) surrounded by the < and > 
characters. If you’re familiar with HTML,

is an example of a start tag. Similarly, an 
end tag example is

. Table 3.1 shows some examples of element tags and their 
usage.
Table 3.1 Element Start and End Tag Syntax
 
Tag
Description
 

An allowable starting tag for the first_tag element

The corresponding ending tag for the first_tag element

Incorrect usage—element names cannot include spaces
<1st_tag>
Incorrect usage—element names cannot begin with a number

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Incorrect usage—spaces are not allowed between the forward 
slash and element name
 
Keep in mind that XML is case sensitive. Element names must therefore open and close 
with identical cases. For example:

110 Main Street

is not acceptable whereas each of the following examples is acceptable:

110 Main Street

110 Main Street

110 Main Street

Also keep in mind that each of these is treated separately. From a parser’s point of view, 
each of these examples is a different type of element.

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