*repeats the group contents below any number of times:
\s+any whitespace character, repeated at least once
\d+a digit, repeated at least once
\h+any horizontal whitespace character, repeated at least once
?matches at most one character from the set below:
-the literal - (4510 / 558 / 2D16)
+the literal + (4310 / 538 / 2B16)
\d+a digit, repeated at least once
Non-Capturing Group(?:\.\d+)? ?repeats the group contents below at most once:
\.the literal . (4610 / 568 / 2E16)
\d+a digit, repeated at least once