Re: Towards a classification system for uses of the Private Use Area

From: Kenneth Whistler (
Date: Sun Apr 28 2002 - 18:06:47 EDT

William Overington continued:

> Then, in order to apply the classification system to any plain text file,
> the file needs to contain some classification characters near the start.
> For a file using the Egyptian hieroglyphics characters, the following
> sequence would be needed.
> U+F35B U+F333 U+F330 U+F330 U+F331 U+F35D

Why not simply insert the following text at the top of the file or page:

"This text includes PUA characters which require the use of the
 font XXX.ttf for proper display, accessible at http://xxx/yyy/"

This accomplishes everything you indicate below, without the need
for a semi-standard agreement on U+FE.. characters, without any
"findpuac.ttf" font required to read the labelling, and without
any need for maintenance of a "type tray" registry someplace that
people would have to apply to to get their type tray identification

> Suppose then that one day someone comes across a plain text file and within
> that plain text file are character codes from the Private Use Area and that
> person has no idea as to which character set those character codes may be
> intended to represent.

Problem obviated by the alternative approach.

> So, the person looks at that file using a word processing program and
> chooses to use a specially made fount named findpuac.ttf (that is, the find
> private use area classification fount) which has all characters as zero
> width except for the eighteen characters in the U+F3.. block which I
> mentioned in my previous posting, those eighteen characters being
> implemented in the findpuac.ttf fount as having analysis glyphs as detailed
> in my previous posting.

Unneeded in the alternative approach.

> The screen display gives a code of C001 which the
> person can look up in a web based reference list

Unneeded in the alternative approach.

> and there finds out that it
> is in fact a particular character set for cuneiform characters. The web
> based reference list contains a link to a website from which the person
> downloads a copy of a special fount that contains the cuneiform characters.

Directly readable in the original document using the alternative approach.

> The plain text file is then displayed using that fount.

Same in both approaches.

> That fount has the
> eighteen characters in the U+F3.. block which I mentioned as being zero
> width, so that they do not affect the display at all when the file is
> displayed.

Unnecessary in the alternative approach.

> So, I suggest that the system is not too complex at all to implement and
> use.

The existence of a *much* simpler alternative approach indicates to me
that it is indeed too complex, and that the availability of the obvious
alternative will preclude heading in this direction.


This archive was generated by hypermail 2.1.2 : Sun Apr 28 2002 - 18:54:09 EDT