Private Use areas

[Richard Wordingham via Unicode]

On Thu, 23 Aug 2018 17:39:15 +0200
Philippe Verdy via Unicode <unicode at unicode.org> wrote:

> You make a confusion: I do not propose "hacking" existing codes, but
> instead adding new codes for private variations. It's then up to PUV
> sequence authors to choose an appropropriate base character that can
> have the properties they want to be inherited by the private-use
> variation sequence, or to choose a base character that will provide
> some reasonnable reading if rendererd as is (by renderers or fonts
> not implementing the pricate viaration sequence, give nthat they will
> also append a symbol for the PUV itself after the standard character).

Variation sequences cannot be used to add new characters.  Most PUA
characters are used to represent new characters.  A
standard-conformant private variation sequence would generally achieve
the same effect as could be achieved by a font feature (typically one
of the cvxx, though possibly one of the ssxx), though using font
features would be fiddlier and have more limited support, and variation
sequences would facilitate data processing.

Richard.