^start of string
1?optionally matches the literal 1 (4910 / 618 / 3116)
\s?optionally matches any whitespace character
\(the literal ( (4010 / 508 / 2816)
\d{3}a digit, repeated exactly 3 times
\)the literal ) (4110 / 518 / 2916)
\s?optionally matches any whitespace character
\d{3}a digit, repeated exactly 3 times
\s?optionally matches any whitespace character
-?optionally matches the literal - (4510 / 558 / 2D16)
\d{4}a digit, repeated exactly 4 times
$end of string