Regular Expressions 101

^start of line

Non-Capturing Group(?:19|20)?

?repeats the group contents below at most once:

1st Alternative19

19the literal text 19

2nd Alternative20

20the literal text 20

\d{2}a digit, repeated exactly 2 times

Negative Lookahead(?!000|500|36[7-9]|3[7-9]\d|86[7-9]|8[7-9]\d)

1st Alternative000

000the literal text 000

2nd Alternative500

500the literal text 500

3rd Alternative36[7-9]

36the literal text 36

Character Class[7-9]

7-9one character from 7 (55₁₀) to 9 (57₁₀)

4th Alternative3[7-9]\d

3the literal 3 (51₁₀ / 63₈ / 33₁₆)

Character Class[7-9]

7-9one character from 7 (55₁₀) to 9 (57₁₀)

\da digit

5th Alternative86[7-9]

86the literal text 86

Character Class[7-9]

7-9one character from 7 (55₁₀) to 9 (57₁₀)

6th Alternative8[7-9]\d

8the literal 8 (56₁₀ / 70₈ / 38₁₆)

Character Class[7-9]

7-9one character from 7 (55₁₀) to 9 (57₁₀)

\da digit

Character Class[0-35-8]

0-3one character from 0 (48₁₀) to 3 (51₁₀)

5-8one character from 5 (53₁₀) to 8 (56₁₀)

\da digit

\d{4}a digit, repeated exactly 4 times

Character Class[vVxX]

vthe literal v (118₁₀ / 166₈ / 76₁₆) (case sensitive)

Vthe literal V (86₁₀ / 126₈ / 56₁₆) (case sensitive)

xthe literal x (120₁₀ / 170₈ / 78₁₆) (case sensitive)

Xthe literal X (88₁₀ / 130₈ / 58₁₆) (case sensitive)

$end of line

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?:19|20)?\d{2}(?!000|500|36[7-9]|3[7-9]\d|86[7-9]|8[7-9]\d)[0-35-8]\d\d\d{4}[vVxX]$

New

Format should be 
937962723V
 or 
937962723X
 or any 11 digit number according to the current format.
19345678901x

Regular Expression

Extraction