Adam Kerman wrote:00
>>Anth>>To this day, in the overlaid areas with mandatory 10d home NPA
>>dialing, the 1 dialing prefix is still mandatory.
>But remember that NOT ALL of northern Illinois (or northwestern Indiana)
>are yet on a mandatory (1+)ten-digit dialing format, since the 708/464
>overlay and the 312 & 773 / USA (872) overlay have NOT yet taken effect.
>NANPA hasn't even worked out any dates with the Illinois Commerce
>Commission or the telephone industry doing business in the Chicago metro
>area for such overlays and (1+)ten-digit mandatory.
Checking PL-195, which announced the overlay code assignments years in advance, there's a 30-day notice period before assigning the first prefix in the overlay code upon exhaust of all existing codes. Hm. They haven't even assigned test numbers.
Checking PL-309 and 296, area code 219 uses 1 as a toll barrier. Local calls (both home and foreign NPA) do not use "1" but all toll calls require 1 plus 10 digits. Foreign NPA local calls are 10 digit. So with care, it is possible to avoid confusion without using 1 for all calls.
It doesn't say if local home NPA can be dialed as 10 digits or if local or foreign NPA can be dialed as 1+10 digits permissively.