\S+any character that is not Unicode whitespace, repeated at least once
/INthe literal text /IN (case sensitive) \ba Unicode word boundary
Non-Capturing Group(?:(?!\S+/IN\b).)+ +repeats the group contents below at least once:
Negative Lookahead(?!\S+/IN\b) \S+any character that is not Unicode whitespace, repeated at least once
/INthe literal text /IN (case sensitive) \ba Unicode word boundary
.any Unicode character (except for line terminators)
\S+any character that is not Unicode whitespace, repeated at least once
/NNPthe literal text /NNP (case sensitive) \ba Unicode word boundary
g modifier: global. Finds all matches instead of stopping after the first