\ba Unicode word boundary
ACCthe literal text ACC (case sensitive) Non-Capturing Group(?:\s+TASKS)? ?repeats the group contents below at most once:
\s+a Unicode whitespace character, repeated at least once
TASKSthe literal text TASKS (case sensitive) \s+a Unicode whitespace character, repeated at least once
\d{2}a Unicode decimal digit, repeated exactly 2 times
-the literal - (4510 / 558 / 2D16)
\d{2}a Unicode decimal digit, repeated exactly 2 times
-the literal - (4510 / 558 / 2D16)
\d{2}a Unicode decimal digit, repeated exactly 2 times
-the literal - (4510 / 558 / 2D16)
\d{3}a Unicode decimal digit, repeated exactly 3 times
-the literal - (4510 / 558 / 2D16)
Character Class[A-Z0-9]{0,3} {0,3}matches between 0 and 3 characters from the set below:
A-Zone character from A (6510) to Z (9010) (case sensitive)
0-9one character from 0 (4810) to 9 (5710)
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