[uievents] Issue: What is an 'appropriate' Unicode code point? marked as i18n-comment

r12a has just labeled an issue for https://github.com/w3c/uievents as 
"i18n-comment":

== What is an 'appropriate' Unicode code point? ==
5.3.6. Guidelines for selecting key values
https://w3c.github.io/uievents/#keys-guidelines

> If the key generates a printable character, and there exists an 
appropriate Unicode code point, then the key attribute MUST be a 
string consisting of the char value of that character.

What constitutes an 'appropriate' Unicode code point here?  Is it 
'something other than tab or linefeed'?  Or is it a code point that is
 not a control character? Or perhaps a code point that is defined in 
Unicode?


See https://github.com/w3c/uievents/issues/119