\ba Unicode word boundary
\d{1,2}a Unicode decimal digit, repeated between 1 and 2 times
.the literal . (4610 / 568 / 2E16)
/the literal / (4710 / 578 / 2F16)
-the literal - (4510 / 558 / 2D16)
\d{1,2}a Unicode decimal digit, repeated between 1 and 2 times
\1the text saved by group 1
Non-Capturing Group(?:\d{4}|\d{2}) \d{4}a Unicode decimal digit, repeated exactly 4 times
\d{2}a Unicode decimal digit, repeated exactly 2 times
\ba Unicode word boundary
g modifier: global. Finds all matches instead of stopping after the first
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string