\d{4}a digit, repeated exactly 4 times
_the literal _ (9510 / 1378 / 5F16)
\da digit
_the literal _ (9510 / 1378 / 5F16)
\d{4}a digit, repeated exactly 4 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