^start of line
Group 1(000[1-9]|00[1-9]\d|0[1-9]\d\d|100\d|10[1-9]\d|1[1-9]\d{2}|[2-9]\d{3}|[1-9]\d{4}|1\d{5}|2[0-6]\d{4}|27[0-4]\d{3}|275[0-6]\d{2}|2757[0-5]\d|275760) 1-9one character from 1 (4910) to 9 (5710)
1-9one character from 1 (4910) to 9 (5710)
\da digit
3rd Alternative0[1-9]\d\d 0the literal 0 (4810 / 608 / 3016)
1-9one character from 1 (4910) to 9 (5710)
\da digit
\da digit
1-9one character from 1 (4910) to 9 (5710)
\da digit
6th Alternative1[1-9]\d{2} 1the literal 1 (4910 / 618 / 3116)
1-9one character from 1 (4910) to 9 (5710)
\d{2}a digit, repeated exactly 2 times
7th Alternative[2-9]\d{3} 2-9one character from 2 (5010) to 9 (5710)
\d{3}a digit, repeated exactly 3 times
8th Alternative[1-9]\d{4} 1-9one character from 1 (4910) to 9 (5710)
\d{4}a digit, repeated exactly 4 times
1the literal 1 (4910 / 618 / 3116)
\d{5}a digit, repeated exactly 5 times
10th Alternative2[0-6]\d{4} 2the literal 2 (5010 / 628 / 3216)
0-6one character from 0 (4810) to 6 (5410)
\d{4}a digit, repeated exactly 4 times
11th Alternative27[0-4]\d{3} 0-4one character from 0 (4810) to 4 (5210)
\d{3}a digit, repeated exactly 3 times
12th Alternative275[0-6]\d{2} 0-6one character from 0 (4810) to 6 (5410)
\d{2}a digit, repeated exactly 2 times
13th Alternative2757[0-5]\d 2757the literal text 2757 0-5one character from 0 (4810) to 5 (5310)
\da digit
-the literal - (4510 / 558 / 2D16)
-the literal - (4510 / 558 / 2D16)
Group 3(0[1-9]|[12]\d|3[01]) Tthe literal T (8410 / 1248 / 5416) (case sensitive)
:the literal : (5810 / 728 / 3A16)
Non-Capturing Group(?::(0\d|[1-5]\d))? Non-Capturing Group(?:.(00\d|0[1-9]\d|[1-9]\d{2}))? $end of line
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