[XeTeX] Lowercase Unicode code points in hyphenation patterns

[Joseph Wright]

On 24/11/2019 18:40, Apostolos Syropoulos via XeTeX wrote:
> 
>    On Sunday, November 24, 2019, 4:21:32 AM GMT+2, David Carlisle <d.p.carlisle at gmail.com> wrote:
>   
>   >the lccode tables are set by the macro layer not the engine code, it
>> reads in The Unicode consortium data file
>> tex/generic/unicode-data/UnicodeData.txt
>> and sets the lccode values and catcode values according to the data there.
> 
> 
>> see
> 
>> tex/generic/unicode-data/load-unicode-data.tex
> 
> Of course these tables are all wrong but this is another problem.For example, this table specifies that the capital form of έ is
> Έ which is wrong because uppercase letters do not get accents,expect when they start a sentence or the name of a person (e.g.,Έλενα). Since the Unicode consortium is not going to change this,I have added the correct \uccodes and \lccodes in xgreek.sty
> Regards,
> A.S.

This has of course come up before, and I'd like to add to the expl3 case 
changers. However, I've not been able to track down any formal statement 
on the case mappings: are they in the UCD, some official publication, ...?

Joseph