Regular expression reference

In auto-redaction, you can supply a single word or regular expression (regex) that Epiq Discover matches and automatically redacts in the selected document images. A regex provides a pattern to match instead of matching a literal word. For example, the following RegEx finds email addresses from a specific company (name@epiqglobal.com).

Example: \w+@epiqglobal.com

To find an email address that begins with firstname.lastname, use the following example. This example specifies the following pattern: first name with any number of characters, a literal period (.), last name with any number of characters, a literal at symbol (@), any number of characters, another literal period (.), and three characters at the end.

Example: \w+\.\w+@\w+\.\w{3}

Use the regex elements in the following table to construct patterns for auto-redaction. The regex must adhere to POSIX extended RE (ERE) or basic RE (BRE) syntax. The following table lists the supported regex terms. Any terms not included in this table might work but are not supported.

String Matches text that contains Example Possible results
a literal word the supplied single word. Use alone or combine with other elements.

Private

(HR) department

Private

HR department
Metacharacter Matches text that contains Example Possible results
. an alphabetic character, number, or symbol.

a.z

loc....n

a_z

location
\d a number from 0 to 9.

\d

\d{5}(-\d{4})

7

66213 (zip codes)
\D a character that is not a number.

\D\D\D

\D

AbC

%
\w a number, letter, or underscore.

invoice \w-\w\w\w

\w\w\w\w

invoice A-5_1

D234
\W a symbol, but not a letter or number.

\W

\W\W\W

$

*-+=

\s a white space character, like tab, space, or carriage return. a\sb\sc a b c
\S a character that is not a white space character (tab, space, or carriage return). \S\S\S you
\ and a symbol a literal Regular Expression reserved character, such as: \ . { } + ( ) * ? [ ] ^ $ |. Precede the reserved character with a backslash as the escape character.

a\.c

\.\*\?

a.c

.*?

Quantifier Matches text that contains Example Possible results
* the preceding character, 0 or more times.

a*b*c*

misspell*

aaacccc

misspel or misspelll
+ the preceding character, 1 or more times.

at+orney

\d+\.\d\d

 

attorney

10.00 (two digit, two decimal number)
? the preceding character, either 0 or 1 times.

plurals?

honou?r

plurals or plural

honor or honour
{n} the preceding character or group for the specified number (n) of times.

a{3}

\d{5}

aaa

66213
{n,} the preceding character or group the specified number (n) of times or more. A{3,} AAAAAA
{n,m} the preceding character or group the specified number (n) of times, but not more than the maximum (m) times. \d{2,4} 19, 198, or 1984
OR Matches text that contains Example Possible results
| text on either side of the pipe symbol, which behaves similar to an OR operand.

22|33

trade(off|in)

22 or 33

tradeoff or tradein
Group/Choice Matches text that contains Example Possible results
[ ... ] a character or number listed in the brackets.

[ABC]

[123]

A, B, or C

1, 2, or 3
[n - x] a character or number in the supplied range, regardless of order. No more than one match can occur.

[a-z]

\+[0-9]{11}

b

+14528281111
[^n] any character or number other than those listed.

[^a]

[^a-y]

b

z
( ) all of the supplied characters or numbers.

a(dmit)

..(465)

admit

br465
Boundary Matches non-printable characters Example Possible results
^ at the beginning of the extracted text when used outside of square brackets. ^abc abc (at the start)
$ at the end of the extracted text. end$ end (at the end)