^start of line
\Sany character that is not Unicode whitespace
.*any Unicode character (except for line terminators), repeated any number of times
Non-Capturing Group(?:\n[^\S\n]+board add 0/\d+ (?:aaa|bbb))+ +repeats the group contents below at least once:
\na line-feed (newline) character (ASCII 10)
Negated Character Class[^\S\n]+ +matches at least one character outside the set below:
\Sany character that is not Unicode whitespace
\na line-feed (newline) character (ASCII 10)
board add 0/the literal text board add 0/ (case sensitive) \d+a Unicode decimal digit, repeated at least once
the literal (3210 / 408 / 2016)
Non-Capturing Group(?:aaa|bbb) aaathe literal text aaa (case sensitive) bbbthe literal text bbb (case sensitive) \na line-feed (newline) character (ASCII 10)
\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