I suggest that a solution to the problem would be to encode a COMBINING
ITALICIZER character, such that it only applies to the character that it
immediately follows. So, for example, to make the word apricot become
displayed in italics one would use seven COMBINING ITALICIZER
characters, one after each letter of the word apricot. The display could
be sorted out using an OpenType font by treating each pair of a letter
and a COMBINING ITALICIZER as a ligature. If, say, the glyph name of
COMBINING ITALICIZER were italic then the glyph for c italic could be
c_italic and so plain text might well be copyable from a PDF (Portable
Document Format) document and pasted to WordPad as plain text retaining
the COMBINING ITALICIZER character, depending upon which application
program is used to produce the PDF document and which PDF reader is in
use.
This would seem a workable solution. Many years ago I suggested having
characters that would have been comparable in use in plain text as to
how italics is switched on and off in HTML (Hypertext Markup Language)
yet was advised that such an encoding would make plain text stateful and
thus would not be agreed for encoding. That objection might well still
be the case today. So using a COMBINING ITALICIZER character would avoid
that objection and would also provide a solution that could be
straightforwardly implemented using existing OpenType technology.
William Overington
Wednesday 9 January 2019
