In the following example \keys_set_groups:nnn ignores every key in the meta key "default", while \keys_set_filter:nnn "looks" into the meta key and filters out (as wanted) only the initkey. When I add the default key to the "init" group the output of \keys_set_groups:nnn is correct, but now the filter is wrong. \documentclass{article} \usepackage{expl3} \begin{document} \ExplSyntaxOn \keys_define:nn {mymodule} { initkey .code:n = {init!~}, initkey .groups:n = {init}, laterkey .code:n = {later!~}, laterkey .groups:n = {later}, default .meta:n = {initkey,laterkey}, %default .groups:n = {init}, } % no output, wanted: init! \keys_set_groups:nnn {mymodule} {init} {default} \par % wanted: later! \keys_set_filter:nnn {mymodule} {init} {default} \par \ExplSyntaxOff \end{document} The only work around I found is to create key copies: defaultinit .meta:n = {initkey,laterkey}, defaultlater .meta:n = {initkey,laterkey}, but this doesn't look very elegant. Is there a way to assign the default key to "none and all groups" so that is always processed by both commands? -- Ulrike Fischer http://www.troubleshooting-tex.de/