Case Sensitivity

XML is case sensitive, and this is a very important point for creating 
well-formed documents and for portability.  What this means is that 
XML processors will distinguish upper case letters (A-Z) from 
lower case letters (a-z).  For example, the following will result in 
an error because the start tag <name> and the end tag </Name> are 
not recognized as the same.

<name>
	<first>John</first>
	<last>Doe</last>
</Name>

File: Chapter 2\Employees3.htm code snippet

The above would result in an error regarding unmatched tags.  
The following screen captures show how both XML Notepad 
and IE5 react to the error.

File: Chapter 2\Employees3.htm in XML Notepad

File: Chapter 2\Employees3.htm in IE5

The reason that XML is case sensitive is very interesting.  Most 
ASCII based text systems will convert text into upper case so that 
case-sensitivity is not an issue. 

However, XML is a portable standard, and by portable we mean 
language independent.  This is the very reason why XML supports 
Unicode, and not ASCII.  This makes it impossible to do any 
conversion with confidence since some character set conversions 
may behave differently than expected.  XML defaults to lower case.  
It is recommended that you always use lower case as well.

Tip:  	Always use lowercase instead of mixed case.  This results 
in consistency throughout your code and makes it more portable