1. A computer-implemented method, comprising: receiving a search request that includes one or more user-specified search keywords; identifying a first document and a second document, each document having at least one chunk that satisfies the search keywords, wherein a first text string in the first document has a first content type and the first text string in the second document has a second content type that is different from the first content type; receiving a user request to replace the first text string with a second text string; and substituting the second text string for the first text string in the first document and the second document, wherein the replacing second text string in the first document has the first content type and the replacing second text string in the second document has the second content type.