In addition to device independent events, XForms also provides another powerful feature by its model-view-controller design. XForms separates content from presentation while embedding relevant meta data in user interface constructs.
XForms provides the following meta data:
label for the user interface control
hint help text for the user interface control
help help text for the user interface control
XForms also encourages intent-based authoring by introducing these constructs:
group to group a set of user interface controls
switch , and case which can be used to hide or reveal logical groups of controls
case includes a Boolean attribute called selected that allows the group of controls within that case to become active. This is important to assistive technologies, such as a screen reader, which would monitor the document to determine when to speak selected elements. If none of the cases within the switch are selected, the first case in document order becomes active by default. How those elements are rendered visually is of no consequence. The semantics are preserved.
For an in-depth look at XForms a great book to read is:
XForms: XML Powered XForms by TV Raman