*repeats the group contents below any number of times:
,the literal , (4410 / 548 / 2C16)
!?optionally matches the literal ! (3310 / 418 / 2116)
\[the literal [ (9110 / 1338 / 5B16)
\da digit
-the literal - (4510 / 558 / 2D16)
\da digit
\]the literal ] (9310 / 1358 / 5D16)