<?root-attributes any-name1="any-value2" any-name2="any-value2"?>
It specifies the additional attributes for the root element of the generated output, which depends on the device types.
Currently, only Ajax devices support this feature and the root element is the html tag. In other words, the attributes specified in the root-attribute directives will become the attributes of the html element of the generated output. For example,
<?root-attributes xmlns:v="urn:schemas-microsoft-com:vml"?>
will cause the HTML output to be generated with the following snippet
<html xmlns="http://www.w3.org/1999/xhtml"xmlns:v="urn:schemas-microsoft-com:vml">
Note: xmlns="http://www.w3.org/1999/xhtml" is always generated.
Note: If the value is specified with an EL expression and it is evaluated to null, the corresponding attribute won't be generated.