RE: more flexible pipeline for new scripts and characters

From: Peter Constable <>
Date: Sun, 20 Nov 2011 19:28:12 +0000

From: [] On Behalf Of Doug Ewell

> This is one of the things the PUA is for. Unfortunately, it has become
> very popular to tell people to stay away from the PUA, that it is evil
> and unsuitable for any sort of interchange

That's an overstatement. Implementing PUA can be very problematic _in some scenarios_. For instance, suppose an OS vendor were to implement PUA characters for thousands of ideographs, in effect assuming that a large portion of PUA were those ideographs. That would lead to a number of problems, including the following:

- users interested in using a PUA character for some other purpose would have problems

- data would not interoperate between that OS and other platforms

- if those characters later are later added to Unicode, users, app developers and the OS vendor have to deal with problems of data using alternate representations

At the opposite extreme, suppose an individual user or app developer needs to represent something as a PUA character and there is no broad interchange of data using that PUA character, then none of the problems mentioned above arise.

Of course, in between there is a range of scenarios involving varying degrees of data interchange. The risks will vary depending on the scenario. Anyone considering use of PUA in that case should evaluate the potential risks and costs of their options.

Received on Sun Nov 20 2011 - 13:34:19 CST

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