XML
可以单独使用（作为validateDTD和validateSchema的目标）或和一个XPath表达式参数（这使得它成为有效的目标对于任何函数接受纯文本）。例如使用XPath：
SecDefaultAction log,deny,status:403,phase:2
SecRule REQUEST_HEADERS:Content-Type ^text/xml$ \
phase:1,t:lowercase,nolog,pass,ctl:requestBodyProcessor=XML
SecRule REQBODY_PROCESSOR "!^XML$" skipAfter:12345
SecRule XML:/employees/employee/name/text() Fred
SecRule XML:/xq:employees/employee/name/text() Fred \
id:12345,xmlns:xq=http://www.example.com/employees
第一个XPath表达式不使用名称空间。这将匹配像下面这样的加载：
<employees>
<employee>
<name>Fred Jones</name>
<address location="home">
<street>900 Aurora Ave.</street>
<city>Seattle</city>
<state>WA</state>
<zip>98115</zip>
</address>
<address location="work">
<street>2011 152nd Avenue NE</street>
<city>Redmond</city>
<state>WA</state>
<zip>98052</zip>
</address>
<phone location="work">(425)555-5665</phone>
<phone location="home">(206)555-5555</phone>
<phone location="mobile">(206)555-4321</phone>
</employee>
</employees>
第二个XPath表达式使用名称空间。这将匹配下面这样的加载：
<xq:employees xmlns:xq="http://www.example.com/employees">
<employee>
<name>Fred Jones</name>
<address location="home">
<street>900 Aurora Ave.</street>
<city>Seattle</city>
<state>WA</state>
<zip>98115</zip>
</address>
<address location="work">
<street>2011 152nd Avenue NE</street>
<city>Redmond</city>
<state>WA</state>
<zip>98052</zip>
</address>
<phone location="work">(425)555-5665</phone>
<phone location="home">(206)555-5555</phone>
<phone location="mobile">(206)555-4321</phone>
</employee>
</xq:employees>
请注意第二个例子使用不同的命名空间。
要了解更多有关XPath我们建议参考以下资源：
XPath的标准 http://www.w3.org/TR/xpath
XPath教程 http://www.zvon.org/xxl/XPathTutorial/General/examples.html