Decimal Encoding Specification, version 0.96 Copyright (c) IBM Corporation, 2003. All rights reserved. ©	Draft of 10 Oct 2003
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Appendix B – Changes

This appendix documents changes since the first circulation of the ‘Strawman 3’ proposal (7 November 2002). It is not part of the specification.

It is pointed out that, although infinities and NaNs should be recognized as such based on only the first byte of the number, arithmetic may well be required to fully define all bits of an infinite or NaN result (for example, by clearing the remaining bytes to 0).
A note has been added to Appendix A, pointing out that the coefficient can be considered to have an internal decimal point if an appropriate change to the bias is made.
The term U_max has been renamed E_limit for consistency with other documents.

The exponent range of all three formats has been expanded by making the largest normal number be the largest representable number. This also simplifies the calculations of E_max and bias. There are now no ‘supernormal’ values, and one value of encoded exponent is always unused (and is therefore available for future expansion of the encoding scheme).
The names compact, single precision, and double precision have been replaced by the names decimal4, decimal8, and decimal16 respectively, to avoid confusion with the binary floating-point formats.

The distinction between signaling NaN and quiet NaN, using the top bit of the exponent continuation field, has been made part of the specification.
For an Infinity, the top bits of the exponent continuation field have been defined to be 0 (instead of 1). This places Infinity logically adjacent to the finite numbers, and allows Infinities to have all bits zero after the combination field.

During the IEEE 754r committee meeting in January 2003, the following changes were agreed.

Signaling NaN has been removed.
Redundant Densely Packed Decimal encodings are permitted in operands.
The value of E_max is raised by one for all encodings (leaving E_min unchanged), hence using all exponent values available.

These changes mean that all possible bit patterns in the formats are valid.

During the IEEE 754r committee meeting in February 2003, the following changes were agreed.

Signaling NaN has been restored.
The names decimal4, decimal8, and decimal16 have been replaced by the names decimal32, decimal64, and decimal128 respectively.