categories My suggestion that dummify(x) should be a synonym for dummify(x, 1) was intended as a way of avoiding a backward-incompatible change. I assume that under your scheme dummify(x) would translate to dummify(x, n) with n=NA, which would be backward-incompatible. I acknowledge that your syntax is more general and has advantages. My proposal reflected a desire to use the dummify inside functions when it is a little tedious, though not difficult, to work out the maximum value that can be dropped. However, this can be got round by matrix xvals=values(x) scalar mxval=maxc(xvals) list dlist=dummify(x, mxval) so I would be happy with your suggestion. Gordon