Does readonly apply to radio buttons and checkboxes?

Does the 'readonly' attribute apply to <input>s with a type other than 
text and password? From 
<http://www.w3.org/TR/html4/interact/forms.html#edef-INPUT>:

readonly    (readonly)     #IMPLIED  -- for text and passwd --

But I fail to see why it should not apply to checkbox and radio as well.

/Jonas