^start of line
\+?optionally matches the literal + (4310 / 538 / 2B16)
\d{3}a digit, repeated exactly 3 times
?optionally matches the literal (3210 / 408 / 2016)
\d{3}a digit, repeated exactly 3 times
?optionally matches the literal (3210 / 408 / 2016)
\d{3}a digit, repeated exactly 3 times
?optionally matches the literal (3210 / 408 / 2016)
\d{3}a digit, repeated exactly 3 times
$end of line
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