> >TUS does not prevent anyone to put noncharacter code points in Unicode > >strings. As a matter of fact, p. 23 of TUS 3.0 reads "U+FFFF is reserved > for > >private program use as a sentinel or other signal." I would expect this > to > >hold true for the noncharacters that were introduced later too. It may > not > >fit your needs if you're looking for a character, but it is available for > >use by applications. > > But it is *not* available to *users* to put into lists to make certain > elements sort at the end.
When dealing with user-specified lists, I would if possible introduce some markup so that my application can deal with those two special cases (lowest/highest) as it wishes internally without burdening the user with the need to enter an improbable (in her everyday's context) codepoint. YA