Is there a way to prevent write.csv to transform the column names a la make.names? I mean, if I write the code: x <- structure (NULL) x [["a+b"]] <- c (1,2) write.csv (x, file = "foo.csv", row.names = FALSE, quote = FALSE) I get in foo.csv: a.b 1 2 but I want: a+b 1 2 Any suggestions? Cheers, -- Rafael Laboissiere