It took certain phone book publishers a while to figure that out.
On a recent stay at a motel in New Mexico, I examined the 2007 edition of the Colvis/Portales/Tucumcari telephone directory (a "Five Star Phone Book" it modestly claimed). It contained the following instructions for calling Mexico:
| Most locations in Mexico can be reached by using the | international diallng (011+) instructions. If you cannot use | international dialing from your telephone, some Mexican cities | can be dialed using special access codes with city codes (see | following list for some City Codes). | | MEXICO CITY dial: | 1 + 90 + 5(the City Code) + local numbers | | NORTHWEST MEXICO dial: | 1 + 70 + City Code (2 or 3 digits beginning with "6") + Local | number
That directory was published in 2007, almost 13 years after 706 and 905 were reclaimed and reassigned as area codes in Georgia and Ontario!
Five Stars indeed.
Neal McLain