{4}matches exactly 4 characters from the set below:
A-Zone character from A (6510) to Z (9010) (case sensitive)
a-zone character from a (9710) to z (12210) (case sensitive)
0-9one character from 0 (4810) to 9 (5710)
+the literal + (4310 / 538 / 2B16)
/the literal / (4710 / 578 / 2F16)