?repeats the group contents below at most once:
:?optionally matches the literal : (5810 / 728 / 3A16)
%?optionally matches the literal % (3710 / 458 / 2516)
\w{2,}any word character, repeated at least 2 times
\/?optionally matches the literal / (4710 / 578 / 2F16)
\.the literal . (4610 / 568 / 2E16)
\w{2,3}any word character, repeated between 2 and 3 times