The search and replace function in the data processing shape will find quotes and other special characters by prepending a backslash (\). this is also the case for the replacement string.
Example: I want to include double quotes in JSON field value for an API call. Especially helpful if your capturing error messages which you may have no control over.
Since double quote is reserved, it will break the API call unless escaped. Configure the search and replace function to find \" and replace with \\\" - note backslash is also a special character and so also must be escaped. If the input string was something like Error code "Some code" the output of search and replace will be Error code \"Some code\". The backslash will be stripped out of the value when the JSON is deserialized resulting a an object value of Error code "Some code" which is the desired result.