2.2.1 [DOM Level 2 - HTML] Section 1.1, Introduction


The specification states:

 The interfaces found within this section are not mandatory. A DOM application may 
 use the hasFeature(feature, version) method of the DOMImplementation interface with 
 parameter values "HTML" and "2.0" (respectively) to determine whether or not this 
 module is supported by the implementation. In addition to the feature string 
 "HTML", the feature string "XHTML" (version string "2.0") can be used to check if 
 the implementation supports XHTML (this is equivalent to checking the features 
 "XML" and "HTML"). In order to fully support this module, an implementation must 
 also support the "Core" feature defined. Please refer to additional information 
 about conformance in the DOM Level 2 Core specification.

All Document Modes (Internet Explorer 7 and Internet Explorer 8)

The hasFeature method returns FALSE when the feature parameter is set to "HTML" and the version parameter is set to "2.0".