Hi, \checkparameters seems broken in the current beta. The following example used to work at least with version 2012.06.13 --------------------------------------------------------------------------------- \def\myCom[#1]{% \checkparameters[#1] \ifparameters \getparameters[do][one=1,two=2,#1] \doone\ \dotwo \else #1 \fi } \starttext \myCom[one] \myCom[one=one,two=two] \stoptext --------------------------------------------------------------------------------- … while with the current beta (2012.08.02) it results in: system > tex > error on line 11 in file testcheckparameters.tex: Undefined control sequence ... 1 \def\myCom[#1]{% 2 \checkparameters[#1] 3 \ifparameters 4 \getparameters[do][one=1,two=2,#1] 5 \doone\ \dotwo 6 \else 7 #1 8 \fi 9 } 10 \starttext 11 >> \myCom[one] 12 13 \myCom[one=one,two=two] 14 \stoptext \checkparameters ..._helpers_get_empty_parameters #1=@@\_e_o_s_ \myCom [#1]->\checkparameters [#1] \ifparameters \getparameters [do][one=1,t... l.11 \myCom[one] Thanks in advance, Daniel