OverStrike control character

[James Kass]

Richard Wordingham wrote,

 > Wouldn't this violate the character identity of U+2408?

U+2408 SYMBOL FOR BACKSPACE
Using a symbol for backspace in running text as a symbol for backspace 
to illustrate a notational convention for overstriking shouldn’t violate 
its character identity.  It was offered in response to the objections of 
using the ASCII back space or other control characters because they are 
not graphic characters.  U+2408 is a graphic character.

 > The proper mechanism would be to use a PUA character.

This would only be true if the data wasn’t intended to be interchangeable.

Abraham Gross wrote,

 > (‹m↶l› or ‹m￩l› might be a good alternative)

Since they’re graphic characters either should be workable.  As long as 
our hypothetical user community agrees on a notational convention, 
acceptable display should be possible with existing technology.  It 
might be interesting to see if people with a demonstrable need to 
exchange overstruck material in plain-text, such as epigraphers, already 
have an established convention.

In numismatics, Yeoman’s catalogs simply spell it out for overstruck 
dates, such as “1918D, 8 over 7”.