XFA

XFA (XML Forms Architecture) is a deprecated format used in PDF files. Most PDF viewers are incompatible and will show only a message such as "The document you are trying to load requires Adobe Reader 8 or higher."

Specifications

 * XML Forms Architecture (XFA) Specification, Version 3.3 (2012-01-09)
 * XML Forms Architecture (XFA) Specification, Version 3.1 (2009-11-16)
 * XML Forms Architecture (XFA) Specification, Version 3.0 (2009-03-12)
 * XML Forms Architecture (XFA) Specification, Version 2.8 (2008-10-23)
 * XML Forms Architecture (XFA) Specification, Version 2.7 (2008-02-29)
 * XML Forms Architecture (XFA) Specification, Version 2.6 (2008-01-25)
 * XML Forms Architecture (XFA) Specification, Version 2.5 (2007-06-08)
 * XML Forms Architecture (XFA) Specification, Version 2.4 (2006-09-11)
 * XML Forms Architecture (XFA) Specification, Version 2.2 (2005-06-07)
 * XFA Specification, Version 2.2 draft (2004-10-01)
 * XFA Specification, Version 2.1 draft 3 (2004-07-01)