L2/12-145
Source: Mark Davis
Date: April 27, 2012
Subject: Document fractional weights for implicit values

There was the following email after UCA came out, which points
out a hole in our documentation. We need to document the algorithm
used to generate the fractional weights for implicit values. Those
have to be aligned with the values used for the decompositions of
characters containing any character with an implicit weight (such
as Han characters). Like other UCA weights, these may change with
each new version of UCA (and *will* change whenever the ranges of
Han characters change).


Tom Hughes wrote:

Is there any documentation available on how to handle implicit
weights when using the Fractional UCA mappings?

I can see there is a range reserved from E0 04 06 to E4 DF 7E 20
for implicit weights, and UTS #10 tells me how to generate normal
weights for characters that aren't explicitly listed but I haven't
managed to find anything that tells me how to generate the
corresponding fractional weights for them?