All underline
handling in Tk standard dialogs is now done with "magic ampersands".

[[As of which version?]]








The experts in this are [A/AK] and [DKF].  The latter has explained,
"'Ampersand magic' is a way of encoding the character to underline in a button,
label, menu etc. in the string.  It is easiest to see how it works by looking at
an example:

  If the string to show is 'Save As...' and the letter to underline is the 'A'
  in 'As...' then the ampersand-magic-ed string is 'Save &As...'

  If the string to show is 'Quit' and the letter to underline is 'Q', then the
  ampersand-magic-ed string is '&Quit'.

IIRC, this sort of thing came originally from Windows, and it is rather a good
idea because it makes it much easier to set up underlines for labels (where real
ampersands tend to be fairly rare), particularly compared with counting
characters to get to the right spot.  I don't remember the exact details of Tk's
implementation but I think it is done through extra procedures and is just used
for strings for Tk's standard dialogs coming from the message catalog."











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[[Bring Anton's example code from "[msgcat and shortcut keys]" here.]]






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[[But [Perl]/Tk uses '^' in place of '&'?  What's going on?]]
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[RS] thought the TCT had decided to use the Unicode "non-spacing underline" for this function? The advantage would have been that the hot key could be easily parsed out, while such a string would not have to be modified at all to display the underline - self fulfilling data prophecy...