\ba Unicode word boundary
+matches at least one character from the set below:
a-zone character from a (9710) to z (12210) (case sensitive)
A-Zone character from A (6510) to Z (9010) (case sensitive)
\ba Unicode word boundary
*the literal (3210 / 408 / 2016) , repeated any number of times
\1the text saved by group 1
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