On Saturday, March 8, 2014 8:19:54 PM UTC-6, Tim Peters wrote
That would be true if the standard explicitly forbade extensions (any
optional operation or behavior not specified by the standard). But there are no standards like that ;-) To comply with a standard, there just needs to be _some_ way to "spell" all the behaviors the standard mandates.
The IEEE 854 1987 is just such a standard (Mike Cowlishaw's extension).
The generalized IEEE 754 2008 standard might not have as much wiggly room.