\d{4}a Unicode decimal digit, repeated exactly 4 times
\s+a Unicode whitespace character, repeated at least once
Negated Character Class[^\d]+ +matches at least one character outside the set below:
\da Unicode decimal digit
,the literal , (4410 / 548 / 2C16)
\s+a Unicode whitespace character, repeated at least once
Negated Character Class[^\d]+ +matches at least one character outside the set below:
\da Unicode decimal digit
\s+a Unicode whitespace character, repeated at least once
Group 4(\d+(?:\/[^\d\s]*)?) \d+a Unicode decimal digit, repeated at least once
Non-Capturing Group(?:\/[^\d\s]*)? ?repeats the group contents below at most once:
\/the literal / (4710 / 578 / 2F16)
Negated Character Class[^\d\s]* *matches any number of characters outside the set below:
\da Unicode decimal digit
\sa Unicode whitespace character
\.?optionally matches the literal . (4610 / 568 / 2E16)
Non-Capturing Group(?:\s+(\d+\.[^\d\s]*))? ?repeats the group contents below at most once:
\s+a Unicode whitespace character, repeated at least once
\d+a Unicode decimal digit, repeated at least once
\.the literal . (4610 / 568 / 2E16)
Negated Character Class[^\d\s]* *matches any number of characters outside the set below:
\da Unicode decimal digit
\sa Unicode whitespace character
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string
u modifier: unicode. Treats the pattern and subject as UTF-16
x modifier: extended. Ignores unescaped whitespace and comments outside character classes
g modifier: global. Finds all matches instead of stopping after the first