Private Use areas

Adam Borowski via Unicode unicode at
Tue Aug 21 15:15:35 CDT 2018

On Tue, Aug 21, 2018 at 11:03:41AM -0700, Ken Whistler via Unicode wrote:
> On 8/21/2018 7:56 AM, Adam Borowski via Unicode wrote:
> > On Mon, Aug 20, 2018 at 05:17:21PM -0700, Ken Whistler via Unicode wrote:
> > > On 8/20/2018 5:04 PM, Mark E. Shoulson via Unicode wrote:
> > > > Is there a block of RTL PUA also?
> > > No.
> > Perhaps there should be?
> This is a periodic suggestion that never goes anywhere--for good reason.
> (You can search the email archives and see that it keeps coming up.)
> Presuming that this question was asked in good faith...

Oif, looks like mere months of inattentive lurking are not enough (the
thread I got pointed to was from 2011).  Apologies.

> > or perhaps by allocating a new range elsewhere.
> See:
> The General_Category property value Private_Use (Co) is immutable: the set
> of code points with that value will never change.
> That guarantee has been in place since 1996, and is a rule that binds the
> UTC. So nope, sorry, no more PUA ranges.


> The way forward for folks who want to do this kind thing is:
> 1. Define a *protocol* for reliable interchange of custom character property
> information about PUA code points.
> And if the goal for #3 is to get some *system* implementer to support the
> protocol in widespread software, then before starting any of #1, #2, or #3,
> you had better start instead with:
> 0. Create a consortium (or other ongoing organization) with a 10-year time
> horizon and participation by at least one major software implementer, to
> define, publicize, and advocate for support of the protocol.

Heh, good point.  I wonder, perhaps a long-lived consortium tasked with
assigning properties to characters already exists?

So your answer _does_ provide a way to go: any PUA use that's no longer
private, or any problem someone has with character properties, should go
through official channels here instead of inventing an own standard.

With my existing hats on (Debian fonts team member, and someone who messes
with terminals in general) I already have two such itches to scratch.
Thus, it sounds like I should do the research, prepare a write-up, and then
come back to harass you folks with inane questions.  Inventing new solutions
that work around instead of with you is a bad idea...


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