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.
