Ohio stations send a sequential serial number beginning with 001 and their Ohio county.
Non Ohio W/VE stations (including KH6/KL7) send a sequential serial number beginning with 001 and their state or province.
DX stations outside of W/VE send a sequential serial number beginning with 001 and "DX".
Mobile stations are allowed to maintain a continuous sequence of serial numbers for all contacts, or may begin with serial number 001 for each separate geographic area activated. The only requirement is that no serial number be repeated within one geographic area.