Regular Expression in Notepad++

. Matches any character
( This marks the start of a region for tagging a match; so what's inside ( ) you can use in "replace with" using \1, \2 etc.
) This marks the end of a tagged region.
\n Where n is 1 through 9 refers to the first through ninth tagged region when replacing. For example, if the search string was Fred([1-9])XXX and the replace string was Sam\1YYY , when applied to Fred2XXX this would generate Sam2YYY .
\< This matches the start of a word using Scintilla's definitions of words.
\> This matches the end of a word using Scintilla's definition of words.
\x This allows you to use a character x that would otherwise have a special meaning. For example, \[ would be interpreted as [ and not as the start of a character set.
[...] This indicates a set of characters, for example, [abc] means any of the characters a, b or c. You can also use ranges, for example [a-z] for any lower case character.
[^...] The complement of the characters in the set. For example, [^A-Za-z] means any character except an alphabetic character.
^ This matches the start of a line (unless used inside a set, see above).
$ This matches the end of a line.
* This matches 0 or more times. For example, Sa*m matches Sm , Sam , Saam , Saaam and so on.
+ This matches 1 or more times. For example, Sa+m matches Sam , Saam , Saaam and so on.