\w*a Unicode word character, repeated any number of times
\Bnot a Unicode word boundary
zzthe literal text zz (case sensitive) \Bnot a Unicode word boundary
\w*a Unicode word character, repeated any number of times
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