validation - Using a DTD, can an element be declared that allows any XML content? -

I am trying to create a DTD for an XML document. The document has two children- structured data and other unstructured data such as;

  & lt; Doc & gt; & Lt; Structured & gt; & Lt; Foo x = "9" /> & Lt; Foo x = "4" /> & Lt; / Structured & gt; & Lt; Unstructured & gt; & Lt; Hello / & gt; & Lt; World x = "2" & gt; & Lt; Hi msg = "something" /> & Lt; Anything /> & Lt; / World & gt; & Lt; / Unstructed & gt; & Lt; / Doc & gt;   
 I want to create a DTD for the above XML which is  & lt; Unstructured & gt;  Allows the element to contain any valid XML I tried this DTD  
    
 But the errors are generated in this way;  
  No declaration for element is hello element no declaration to the world   
. .etc  
 I  & lt; Unstructured & gt; Do I want to allow any legitimate XML to be included? Is there any way to allow a specific element to contain any reciprocal XML in a DTD?  
 I am using PHP 5.3 DOMDocument :: validate.   
 
 
 No, it is not.  
 The closer you come, the DTD can come by using any  keyword. But  any  matches the mix of # PCDATA and each element declared in DTD. It does not accept undeclared elements; There is not much perception of partial validity in DTDs            / P>