Non-Capturing Group(?:channel:)? ?repeats the group contents below at most once:
channel:the literal text channel: (case sensitive) Negated Character Class[^\S\r\n]* *matches any number of characters outside the set below:
\Sany character that is not Unicode whitespace
\ra carriage return (ASCII 13)
\na line-feed (newline) character (ASCII 10)
Group channel(?P<channel>\d+) \d+a Unicode decimal digit, repeated at least once
>the literal > (6210 / 768 / 3E16)
\s*a Unicode whitespace character, repeated any number of times
\na line-feed (newline) character (ASCII 10)
Non-Capturing Group(?:as:[^\S\r\n]*(?P<as>.+)\n+)? ?repeats the group contents below at most once:
as:the literal text as: (case sensitive) Negated Character Class[^\S\r\n]* *matches any number of characters outside the set below:
\Sany character that is not Unicode whitespace
\ra carriage return (ASCII 13)
\na line-feed (newline) character (ASCII 10)
.+any Unicode character (except for line terminators), repeated at least once
\n+a line-feed (newline) character (ASCII 10), repeated at least once
Group 3(:?image:[^\S\r\n]*(?P<image>.+)\n+)? ?repeats the group contents below at most once:
:?optionally matches the literal : (5810 / 728 / 3A16)
image:the literal text image: (case sensitive) Negated Character Class[^\S\r\n]* *matches any number of characters outside the set below:
\Sany character that is not Unicode whitespace
\ra carriage return (ASCII 13)
\na line-feed (newline) character (ASCII 10)
.+any Unicode character (except for line terminators), repeated at least once
\n+a line-feed (newline) character (ASCII 10), repeated at least once
content:the literal text content: (case sensitive) \n*a line-feed (newline) character (ASCII 10), repeated any number of times
Group content(?P<content>[\s\S]+) +matches at least one character from the set below:
\sa Unicode whitespace character
\Sany character that is not Unicode whitespace
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