Hi, missing "s" (or #1) at the end of \ifparameter. \permanent\tolerant\protected\def\convertbtxdatasettoxml[#1]% - {\clf_convertbtxdatasettoxml{\ifparameter\or#1\else\s!default\fi}} % or current when not empty + {\clf_convertbtxdatasettoxml{\ifparameters\or#1\else\s!default\fi}} % or current when not empty Wolfgang