^start of line
0the literal 0 (4810 / 608 / 3016)
\.the literal . (4610 / 568 / 2E16)
\d{1,3}a digit, repeated between 1 and 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