\ban ASCII word boundary
Php-Auth-the literal text Php-Auth- (case sensitive) Non-Capturing Group(?:Pw|User) Pwthe literal text Pw (case sensitive) Userthe literal text User (case sensitive) :the literal : (5810 / 728 / 3A16)
\s*any whitespace character, 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
\S+any non-whitespace character, repeated at least once
g modifier: global. Finds all matches instead of stopping after the first