\s*any whitespace character, repeated any number of times
Positive Lookahead(?=.*[1-9]) .*any character (except for line terminators), repeated any number of times
1-9one character from 1 (4910) to 9 (5710)
\d*a digit, repeated any number of times
Non-Capturing Group(?:\.\d{1,2})? ?repeats the group contents below at most once:
\.the literal . (4610 / 568 / 2E16)
\d{1,2}a digit, repeated between 1 and 2 times
\s*any whitespace character, repeated any number of times