[R-pkg-devel] .Rd, LaTeX and Unicode

Hi,

I am preparing a package where I would like to use UTF characters in .Rd 
files. When the LaTeX comes to play, I got well known errors e.g.:
! Package inputenc Error: Unicode character ? (U+2202)
(inputenc)??????????????? not set up for use with LaTeX.

It is coherent with what is said on this page 
https://developer.r-project.org/Encodings_and_R.html :
"Since LaTeX cannot handle Unicode we would have to convert the encoding 
of latex help files or use Lambda (and tell it they were in UTF-8)."

But LaTeX can support UTF8 as shown with this small example:

\documentclass{article}
\usepackage[mathletters]{ucs}
\usepackage[utf8x]{inputenc}

\begin{document}
 ??? The vorticity ? is defined as $? = ? ? u$.
\end{document}

I can compile it with my LaTeX without problem. May be you too?
So my suggestion would be to place these two lines somewhere in LaTeX 
header generated by R doc system:
\usepackage[mathletters]{ucs}
\usepackage[utf8x]{inputenc}

Note "utf8x" and not just "utf8" which is crucial for this example.
With a hope that it would fix unicode errors from LaTeX.

Best,
Serguei.