Regular Expressions 101

Pro

^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.

26 tokens

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

Substitution

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