^start of string
Negative Lookahead(?!666|000|9\d{2}) 9the literal 9 (5710 / 718 / 3916)
\d{2}a digit, repeated exactly 2 times
\d{3}a digit, repeated exactly 3 times
{0,1}matches at most one character from the set below:
-the literal - (4510 / 558 / 2D16)
the literal (3210 / 408 / 2016)
\d{2}a digit, repeated exactly 2 times
{0,1}matches at most one character from the set below:
-the literal - (4510 / 558 / 2D16)
the literal (3210 / 408 / 2016)
Negative Lookahead(?!0{4}) 0{4}the literal 0 (4810 / 608 / 3016) , repeated exactly 4 times
\d{4}a digit, repeated exactly 4 times
$end of string, or before its final line terminator