?repeats the group contents below at most once:
^start of string
\d+a digit, repeated at least once
+matches at least one character from the set below:
A-Zone character from A (6510) to Z (9010) (case sensitive)
\d+a digit, repeated at least once
\D+any character that's not a digit, repeated at least once
\Kresets the starting point of the reported match. Any previously consumed characters are no longer included in the final match
g modifier: global. Finds all matches instead of stopping after the first