^start of string
Group KEY(?<KEY>CONF|ESD|TRACKING) CONFthe literal text CONF (case insensitive) ESDthe literal text ESD (case insensitive) TRACKINGthe literal text TRACKING (case insensitive) :the literal : (5810 / 728 / 3A16)
;the literal ; (5910 / 738 / 3B16)
'the literal ' (3910 / 478 / 2716)
\sany whitespace character
\s*any whitespace character, repeated any number of times
.*?any character (except for line terminators), repeated any number of times
\s*any whitespace character, repeated any number of times
Non-Capturing Group(?:L[:;'\s]\s*\K(?<LINE_DATA>.*?))? ?repeats the group contents below at most once:
Lthe literal L (7610 / 1148 / 4C16) (case insensitive)
:the literal : (5810 / 728 / 3A16)
;the literal ; (5910 / 738 / 3B16)
'the literal ' (3910 / 478 / 2716)
\sany whitespace character
\s*any whitespace character, repeated any number of times
\Kresets the starting point of the reported match. Any previously consumed characters are no longer included in the final match
Group LINE_DATA(?<LINE_DATA>.*?) .*?any character (except for line terminators), repeated any number of times
Group INITIALS(?<INITIALS>\*[a-zA-Z]+)? ?repeats the group contents below at most once:
\*the literal * (4210 / 528 / 2A16)
+matches at least one character from the set below:
a-zone character from a (9710) to z (12210) (case insensitive)
A-Zone character from A (6510) to Z (9010) (case insensitive)
\s*any whitespace character, repeated any number of times
$end of string, or before its final line terminator
i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters