BodyOftheMail_Scriptthe literal text BodyOftheMail_Script (case sensitive) \sany whitespace character
=the literal = (6110 / 758 / 3D16)
\sany whitespace character
\[the literal [ (9110 / 1338 / 5B16)
\sany whitespace character
BEGINthe literal text BEGIN (case sensitive) \s*any whitespace character, repeated any number of times
Group 1(\S*(?:\s++(?!END)\S*)*) \S*any non-whitespace character, repeated any number of times
Non-Capturing Group(?:\s++(?!END)\S*)* *repeats the group contents below any number of times:
\s++any whitespace character, repeated at least once
Negative Lookahead(?!END) ENDthe literal text END (case sensitive) \S*any non-whitespace character, repeated any number of times
\s+any whitespace character, repeated at least once
ENDthe literal text END (case sensitive) \sany whitespace character
]the literal ] (9310 / 1358 / 5D16)
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