
You can use meta-characters in the 'Search For' field:

| . | any character except newline | + | one or more times
| * | zero or more times | ? | zero or one time
| {n} | match exact n times | {n,m} | at least n, at most m times
| ~| | pipe: `a~|b` matches a or b | - | hyphen, match a range of chars
| ^ | beginning of a line | $ | end of a line
| [[...] | one of the char's of a set | [[^...] | negated character set
| \b | word boundary | \B | word non boundary
| \d | numeral [[0-9] | \D | non numeral [[^0-9]
| \s | single white space | \S | single non white space
| \w | [[A-Za-z0-9_] | \W | [[^A-Za-z0-9_]
| (...) | grouping are stored as $1..$9 | \. | escape a meta char

The 'Replace with' field can use $1..$9 as a backreference to parentheses of 'Search for' field.

* * *
Example:   

Search for **/abc|def/** will match the word 'abc' or the word 'def'   

Search for **/bwiki/b** will match the word 'wiki' but not the word 'jspwiki'.   

Search for **^[[IVXMDCL]+\.** will match any combination of roman numeral char's followed by a period   

Search for **/(-?\d+)(\d{3})/** and replace with **$1,$2** to insert commas in large integers.

This is the [EditFindAndReplaceHelp]() page. [More info on regular expressions](http://www.regular-expressions.info/javascript.html)and [RegExp Sandbox](http://www.regular-expressions.info/javascriptexample.html)   

