XFDL processors are expected to preserve the XML prolog and epilog, the comments within the XFDL element, and all attributes appearing in start tags but not specifically defined by XFDL. The attributes must be associated with their respective start tags, and the comments must be associated with the respective pages, items, options, or array elements to which they apply. Additionally, all foreign-namespaced elements and attributes must be preserved. The XFDL processor must be able to reproduce these language components for signatures and for saving or transmitting the form.