note moklevat Dang it. No, it's not. <p> This isn't a problem with R, it is a problem with me not thinking. Not only did I forget the split/join, the sort function I originally used only worked because my test case happened to be in alphabetical order. I have updated the original post with functioning code. <p> My apologies to all of you who incorporated the broken code into your mission-critical systems. 589260 589418