[[analysis-pattern_replace-tokenfilter]] === Pattern Replace Token Filter The `pattern_replace` token filter allows to easily handle string replacements based on a regular expression. The regular expression is defined using the `pattern` parameter, and the replacement string can be provided using the `replacement` parameter (supporting referencing the original text, as explained http://docs.oracle.com/javase/6/docs/api/java/util/regex/Matcher.html#appendReplacement(java.lang.StringBuffer,%20java.lang.String)[here]).