\d{1,3}a digit, repeated between 1 and 3 times
Non-Capturing Group(?:\.\d{3})+ +repeats the group contents below at least once:
\.the literal . (4610 / 568 / 2E16)
\d{3}a digit, repeated exactly 3 times
,the literal , (4410 / 548 / 2C16)
\d{2}a digit, repeated exactly 2 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