Dear all, Below is content of attached data file index,ltm,x1,x2,x3,ols 1,0.098527655736295,0.14198429261587,-0.191116784992981,0.22224443607502,-1.13946634223632 Of course trying to open it generates using delimiter ','   longest line: 92 characters   first field: 'index'   number of columns = 6   number of variables: 6   number of non-blank lines: 2 scanning for variable names...   line: index,ltm,x1,x2,x3,ols 'ols' is a reserved word For .csv I can easy change 'ols' anywhere For .xls(x) I have LibreOffice if I use Ubuntu, or if I do not want to be a pirate How about stata, etc? I think, gretl could change such names I mean only reserved words: this would open files that used to  fail to be opened So a new possibility and no backward-incompatible  changes If substitute ols_ for ols everything works Oleh