^start of line
\d{3}a Unicode decimal digit, repeated exactly 3 times
the literal (3210 / 408 / 2016)
Group nom(?P<nom>\w{1,3}) \w{1,3}a Unicode word character, repeated between 1 and 3 times
\.the literal . (4610 / 568 / 2E16)
the literal (3210 / 408 / 2016)
\[the literal [ (9110 / 1338 / 5B16)
Group start(?P<start>.+?) .+?any Unicode character (except for line terminators), repeated at least once
\]the literal ] (9310 / 1358 / 5D16)
the literal (3210 / 408 / 2016)
.*any Unicode character (except for line terminators), repeated any number of times
Group _req_id(?P<_req_id>\d{0,3}) \d{0,3}a Unicode decimal digit, repeated between 0 and 3 times
$end of line
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