Bi-directional text, bold faced font, and other text extension elements are not supported. It is recommended that style sheets are used to create a presentation that is appropriate for the device. But only devices with a local file system can take advantage of file and image input types in forms, so they are not included in the basic feature set. The optgroup and fieldset are redundant means of expressing selection from a list and are not needed in the basic set. The thead , tfoot , tbody , col and colgroup are not supported.
Tables can be difficult to display on small devices.
Frames Frames are not supported. Objects Simple Web clients may support images as embedded objects. The object and param elements are not supported. Limited input capabilities, for example no pointing device, has excluded image-maps. This section is normative.