This is called the Fractional Transit Number - It is a representation of the routing and transit number that can replace the routing and transit number to help identify the institution a check came from in case the MICR line is lost/destroyed.

The first number is called the city/state number, and represents the city and state where the institution is located. Each city has a specific number.

Advantis' Fractional Transit Number is 24-7518/3230 - this represents that we are in Portland, OR, and the remaining numbers are parts of our routing number: 32307518(1)