[Rd] package encoding warning

[baptiste auguie]

Dear list,

I'd like to get rid off a couple of warnings that have appeared in
checking my package on CRAN (I did not find them on my local machine
before submission). What puzzles me is that different platforms return
different warnings, only one of which I recognise as my obvious
mistake. The check results are at
http://cran.r-project.org/web/checks/check_results_planar.html

r-devel-linux-x86_64-gcc-fedora
complains about unused variable in c++ code; this I understand as my
mistake, I'll fix it.

r-patched-windows-ix86+x86_64
is happy, no warning

r-release-macosx-ix86
checking examples ... WARNING
checking a package with encoding 'UTF-8' in an ASCII locale

This one really puzzles me: I have a Encoding: UTF-8 directive in
DESCRIPTION, precisely because I thought it would take care of
encoding issues such as with my surname. What does this mean, and what
should I do about it?

Similarly,
r-oldrel-macosx-ix86
checking whether package 'planar' can be installed ... WARNING
Found the following significant warnings:
Warning: 'DESCRIPTION' file has 'Encoding' field and re-encoding is not possible

has me perplexed.

Best regards,

baptiste