XHTML Basic is a W3C Recommendation and a basic version of XHTML created specifically for mobile devices.
The document type includes the minimal set of modules required to be an XHTML host language document type including the use of images, forms, basic tables, and object support.
The standard is designed for Web clients that do not support the full set of XHTML features such as mobile phones, PDAs, pagers, and settop boxes.
www.w3.org/TR/xhtml-basic