^start of line
Group parameter(?<parameter>[^:]+) Negated Character Class[^:]+ +matches at least one character outside the set below:
:the literal : (5810 / 728 / 3A16)
\:the literal : (5810 / 728 / 3A16)
\s*any whitespace character, repeated any number of times
Non-Capturing Group(?:(?<value>[A-Za-z]+\:\s*[^>]+)) Group value(?<value>[A-Za-z]+\:\s*[^>]+) +matches at least one character from the set below:
A-Zone character from A (6510) to Z (9010) (case sensitive)
a-zone character from a (9710) to z (12210) (case sensitive)
\:the literal : (5810 / 728 / 3A16)
\s*any whitespace character, repeated any number of times
Negated Character Class[^>]+ +matches at least one character outside the set below:
>the literal > (6210 / 768 / 3E16)
\s*any whitespace character, repeated any number of times
Group description(?<description>.*) .*any character (except for line terminators), repeated any number of times
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