Hannes,

> Now I will read the code and put some notes on the Swiki if you don't
> mind.

  Please.  That would be great.

> Especially I will look into stacking and combining various diacritics
> with base vowels.

  As you know, there is a partial, non-complete, code for this.  But I
would say that don't shoot for the complete character combining from
the first place.  We can start with the version that only handles the
characters in the "unicode table," as a character or a presentation
form character.  Afterwards, we can always add more theoretical
combination of diacritics.

  Thank you,

-- Yoshiki