^start of line
.*?any Unicode character (except for line terminators), repeated any number of times
rcpthe literal text rcp (case sensitive) \d+a Unicode decimal digit, repeated at least once
.*any Unicode character (except for line terminators), repeated any number of times
_monthe literal text _mon (case sensitive) \d+a Unicode decimal digit, repeated at least once
.*any Unicode 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