\?the literal ? (6310 / 778 / 3F16)
st=the literal text st= (case sensitive) \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
Positive Lookahead(?=\s*target|$) \s*any whitespace character, repeated any number of times
targetthe literal text target (case sensitive) $end of string, or before its final line terminator
g modifier: global. Finds all matches instead of stopping after the first