Negative Lookbehind(?<!\S) \Sany character that is not Unicode whitespace
\$?optionally matches the literal $ (3610 / 448 / 2416)
Non-Capturing Group(?:\d{1,3}(?:\,\d{3})*)? ?repeats the group contents below at most once:
\d{1,3}a Unicode decimal digit, repeated between 1 and 3 times
Non-Capturing Group(?:\,\d{3})* *repeats the group contents below any number of times:
\,the literal , (4410 / 548 / 2C16)
\d{3}a Unicode decimal digit, repeated exactly 3 times
\.the literal . (4610 / 568 / 2E16)
\d{2}a Unicode decimal digit, repeated exactly 2 times
-?optionally matches the literal - (4510 / 558 / 2D16)
\Sany character that is not Unicode whitespace
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