Where is my character @?

[James Kass via Unicode]

There was a post in an unrelated thread remarking that an unnamed 
writing system used the "at" sign (@) as a letter, and that optimal 
encoding for that orthography was a non-starter.

A question as to whether that writing system was casing went unanswered, 
but a kind list member offered some pointers privately.

The language in question is Koalib, which is spoken in the Sudan. It is 
a casing script and the upper case form uses an upper case "A" with a 
wrap around as in the lower case "@".

The current "solution" is for the users to use the P.U.A. for both upper 
and lower case letters, and fonts such as Doulos SIL support that P.U.A. 
encoding.

A Google search for "Koalib Unicode" finds the following:

Wikipedia:
https://en.wikipedia.org/wiki/Koalib_language

2004-08-25 Lorna A. Priest, Public Review Issue # 40
Revised Proposal to Encode...
http://www.unicode.org/review/pr-40-atsigns.pdf

2004-10-20 Doug Ewell, L2/04-365
The case against encoding the Koalib @-letters
http://unicode.org/L2/L2004/04365-pr40-ewell.pdf

2012-04-17 Karl Pentzlin, L2/12-116
"Capitalized Commercial At" proposal
http://unicode.org/L2/L2012/12116-capital-at.pdf

2018-12-26 Eduardo Marín Silva, L2/19-006
Proposal to encode...
http://www.unicode.org/L2/L2019/19006-capital-at.pdf

It's probably old-fashioned to say that technology should be forced to 
accomodate people rather than the other way around.  But it's good to 
note that efforts are still being made on behalf of the users to make 
progress towards U.C.S. inclusion.