\(the literal ( (4010 / 508 / 2816)
\+?optionally matches the literal + (4310 / 538 / 2B16)
\d{2,3}a digit, repeated between 2 and 3 times
\)the literal ) (4110 / 518 / 2916)
\s?optionally matches any whitespace character
Non-Capturing Group(?:\d{4}[\s*.-]?\d{4}|\d{3}[\s*.-]?\d{3}|\d{2}([\s*.-]?)\d{2}\1\d{2}(?:\1\d{2})?) 1st Alternative\d{4}[\s*.-]?\d{4} \d{4}a digit, repeated exactly 4 times
?matches at most one character from the set below:
\sany whitespace character
*the literal * (4210 / 528 / 2A16)
.the literal . (4610 / 568 / 2E16)
-the literal - (4510 / 558 / 2D16)
\d{4}a digit, repeated exactly 4 times
2nd Alternative\d{3}[\s*.-]?\d{3} \d{3}a digit, repeated exactly 3 times
?matches at most one character from the set below:
\sany whitespace character
*the literal * (4210 / 528 / 2A16)
.the literal . (4610 / 568 / 2E16)
-the literal - (4510 / 558 / 2D16)
\d{3}a digit, repeated exactly 3 times
3rd Alternative\d{2}([\s*.-]?)\d{2}\1\d{2}(?:\1\d{2})? \d{2}a digit, repeated exactly 2 times
?matches at most one character from the set below:
\sany whitespace character
*the literal * (4210 / 528 / 2A16)
.the literal . (4610 / 568 / 2E16)
-the literal - (4510 / 558 / 2D16)
\d{2}a digit, repeated exactly 2 times
\1the text saved by group 1
\d{2}a digit, repeated exactly 2 times
Non-Capturing Group(?:\1\d{2})? ?repeats the group contents below at most once:
\1the text saved by group 1
\d{2}a digit, repeated exactly 2 times