Big Secondary Crunch - DUCET 5.1.0 to DUCET 5.2.0

Between DUCET 5.1.0 and DUCET 5.2.0, a great many secondary elements
(e.g IPA diacritics and less common Khmer combining marks) ceased to be
distinguished even at the tertiary level. Where is the technical
justification for this change? I've looked though the Unicode Technical
Committee motions and not found anything, though it's entirely possible
that I overlooked the relevant resolution. I want to understand the
rationale of what to me looks like a retrograde step.

The bracketing ISO 14651 versions were ISO 14651:2007 Amd 1 and ISO
14651:2011 (3rd edition), which actually matched DUCET 5.1.0 and 6.0.0
respectively.

Richard.
Received on Wed Aug 15 2012 - 17:45:03 CDT