Encyclopaedia MyLands: EditFindAndReplaceHelp

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 and RegExp Sandbox