^start of string
?repeats the group contents below at most once:
\+the literal + (4310 / 538 / 2B16)
0?optionally matches the literal 0 (4810 / 608 / 3016)
1the literal 1 (4910 / 618 / 3116)
\sany whitespace character
\(?optionally matches the literal ( (4010 / 508 / 2816)
\d{3}a digit, repeated exactly 3 times
\)?optionally matches the literal ) (4110 / 518 / 2916)
\sany whitespace character
.the literal . (4610 / 568 / 2E16)
-the literal - (4510 / 558 / 2D16)
\d{3}a digit, repeated exactly 3 times
\sany whitespace character
.the literal . (4610 / 568 / 2E16)
-the literal - (4510 / 558 / 2D16)
\d{4}a digit, repeated exactly 4 times
$end of string