\\the literal \ (9210 / 1348 / 5C16)
xthe literal x (12010 / 1708 / 7816) (case sensitive)
.+any Unicode character (except for line terminators), repeated at least once
*matches any number of characters from the set below:
0-9one character from 0 (4810) to 9 (5710)
the literal (3210 / 408 / 2016)