\s+any whitespace character, repeated at least once
\[the literal [ (9110 / 1338 / 5B16)
.*any character (except for line terminators), repeated any number of times
Positive Lookahead(?=\b\d+) \ban ASCII word boundary
\d+a digit, repeated at least once
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