Binary XML Infoset representations
Well designed binary typed format can be more efficient in processing time and transfer size. Draft TAG finding summarises the issue.
W3C Workshop on Binary Interchange of XML Information Item Sets.
The Workshop concluded that the W3C should do further work in this area, but that the work should be of an investigative nature, gathering requirements and use cases, and prepare a cost/benefit analysis; only after such work could there be any consideration of whether it would be productive for W3C to attempt to define a format or method for non-textual interchange of XML.
New W3C WG formed to study the problem and determine if standardizing a solution would be practicable (TAG: solution is tracked and deferred)