^start of line
\D*any character that's not a digit, repeated any number of times
\Kresets the starting point of the reported match. Any previously consumed characters are no longer included in the final match
\d{2}a digit, repeated exactly 2 times
Positive Lookahead(?=\D*$) \D*any character that's not a digit, repeated any number of times
$end of line
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
i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters