--STARTthe literal text --START (case sensitive) \h*any horizontal whitespace character, repeated any number of times
\Ra newline sequence
\s*any whitespace character, repeated any number of times
.*?any character (except for line terminators), repeated any number of times
\h*any horizontal whitespace character, repeated any number of times
\Ra newline sequence
\s*any whitespace character, repeated any number of times
--ENDthe literal text --END (case sensitive) 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