Le Sun, 13 Feb 2011 16:44:15 +0000, Rodolfo Medina <rodolfo.medina at gmail.com> a écrit : > Strange: it works only with > > \mo{test}[optionaltext] > \mo{test} > > ; instead, with > > \mo{test} > \mo{test}[optionaltext] > > it doesn't. Change \empty to \relax in your test \ifx\@optionalarg\relax -- Arnaud Schmittbuhl