Datasheet

Figure 1-8 shows the HTML display of the preceding HTML coded page, and the XML dis-
played document in Figure 1-7 (the previous example).
Figure 1-8: HTML embeds the code and is less flexible than XML.
❑ Comments: Both XML and HTML use the same character strings to indicate commented
out code:
<!-- This is a comment and will not be processed by the HTML or XML parser -->
Elements
As you have already seen in the previous section, an XML element is the equivalent of an HTML tag. A
few rules apply explicitly to elements:
❑ Element naming rules: The names of elements (XML tags) can contain all alphanumeric
characters as long as the name of the element does not begin with a number or a punctuation
character. Also, names cannot contain any spaces. XML delimits between element names and
attributes using a space character. Do not begin an element name with any combination of the
letters XML, in any combination of uppercase or lowercase characters. In other words,
XML_1,
xml_1, xML_1, and so on, are all not allowed. It will not produce an error to use multiple opera-
tive characters, such as
+ (addition) and – (subtraction), but their use is inadvisable. Elements
least likely to cause any problems are those containing only letters and numbers. Stay away
from odd characters.
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What Is XML?
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