This is a wish list item. It would be nice if one could use \0 or \& in sub and gsub as in vi: gsub("an", ":\\&:", "banana") One can, of course, write the following right now: gsub("(an)", ":\\1:", "banana") But often the this is within a function and the "an" is passed which means that one must use paste to construct the "(an)" argument. Thus: f <- function(x,y) { x <- paste("(", x, ")", sep = "") gsub(x, ":\\1:", y) } simplifies to: f <- function(x,y) gsub(x, ":\\&:", y) I have seen at least one post on r-help where this could have been used to good effect to simplify the answer. It would be neater if \& or \0 could be used instead. Obviously this is not a huge issue but it would be nice.