> Thanks. I should have mentioned my installation version. I already have > a recent installation. The version I have is from 2012/01/31 (I did > a tlmgr update --all). Odd. Does \regex_replace_all:nnN { .* } { \u } \l_tmpa_tl \tl_show:N \l_tmpa_tl (1) trigger an error ("regex/u-no-lbrace", probably) (2) show "u" as the only character in \l_tmpa_tl (3) do something else? Does \def\A{foo} \regex_replace_all:nnN { .* } { \u{A} } \l_tmpa_tl \tl_show:N \l_tmpa_tl correctly set \l_tmpa_tl to "foo"? Regards, Bruno