On Sat, Sep 06, 2008 at 03:51:11PM -0400, William F Hammond wrote:

> Heiko Oberdiek <[log in to unmask]> writes:
> 
> > Hello,
> >
> > what's the unicode code point for \b as accent?
> >
> > U+0331 COMBINING MACRON BELOW/NON-SPACING MACRON BELOW
> > + opposite of \= (U+0304 COMBINING MACRON/NON-SPACING MACRON)
> > - Unicode doesn't have a letter with this accent
> 
> Yes, I think it's this.

Thanks.

> > My guess would be `macron below', \b seems to be inherited
> > from math mode.
> 
> Why do you \b has origin in math mode?  Doesn't \b make its debut
> in section 3.2 of Lamport (2nd edition), "Symbols from Other
> Languages"?  AFAIK the macron is not used as a standard math accent.

I couldn't find a symbol with this accent in the usual encodings,
neither in TDS:tex/latex/base, nor in the files of inputenx.
Also Unicode only has the accent. It seems to be a very
"unusual" language where such accented letters are used.
Thus I don't see, why the good macro name '\b' is wasted for this.

> When the original question is raised in connection with html or xml
> generation, I think it is better to use precombined glyphs where they
> exist.

Unicode bookmarks. I am working on PU encoding stuff in hyperref.

> For example, in a UTF-8-enabled xterm (at least in Linux),
> the two character sequence [b, U-0331] renders equivalently to
> the single character [U-1E07].  The latter (precombined) form
> was supported in some web browsers before support for the two
> character sequence was provided.

Many thanks for the example. That explains, why I couldn't find
accented letters with "macron below". U+1E07 is called:
"LATIN SMALL LETTER B WITH LINE BELOW".
I don't know why "macron below" is called "line below" for
accented letters in the Unicode standard.

Yours sincerely
  Heiko <[log in to unmask]>