rb, ruby, rt | NN n/a IE 5 DOM n/a
Of these three ruby text-related elements, only ruby and rt are officially supported as objects in the IE DOM. But an rb element (even though it has no structural or rendering powers as of IE 6) is also regarded as an element object. Even Netscape 6 sees these as valid HTML element objects (of unknown type). See the ruby element in Chapter 8 for details on the usage of these elements. As scriptable objects, they have no properties or methods beyond a generic HTML element object.
Object Model Reference
    document.getElementById("elementID")
Object-Specific Properties
None.
Object-Specific Methods
None.
Object-Specific Event Handler Properties
None.

filters[ ] | NN n/a IE 4 DOM n/a
Returns an array of all filter objects contained by the current element. Applies only to the following element objects: bdo, body, button, div, fieldset, img, input, marquee, rt, ruby, span, table, td, textarea, and th. See the filter object for referencing syntax.
Value
Array of filter object references.
Default
Array of length zero.