a character for an unknown character

[Christoph Päper]

Richard Wordingham <richard.wordingham at ntlworld.com>:
> 
>> Perhaps the letters for hexadecimal digits should have been encoded
>> separately?
> 
> The idea has been rejected several times.

It has indeed. That’s why two different technologies have to be used to get typographically harmonic hexadecimal numbers, e.g. in CSS:

  .hex {font-variant-numeric: oldstyle-nums; text-transform: lowercase;}
  .hex {font-variant-numeric: lining-nums;   text-transform: uppercase;}

This works well enough for ‘01ef’ or ‘01EF’, but will fail for conventions like ‘0x01ef’ and ‘01EFh’. Hence:

  .hex::before {content: "0x"; text-transform: none;}
  .hex::after  {content: "h";  text-transform: none;}
  .hex::after  {content: "ₕ";}
  .hex::after  {content: "16"; vertical-align: sub; font-size: smaller; line-height: normal;}
  .hex::after  {content: "16"; font-variant-position: sub;}
  .hex::after  {content: "₁₆";}