Possible Clues:

• Parish hieroglyphics found in telephone box
• 05 04 01 for getting in and out of rooms in buildings
• Numerical prefixes
• Some of them are overlaid
• Opening numbers?
• Phone number parts
• Quartet in Mississippi
• 307 for Wyoming and 907 for Alaska
• New York City has six
• Fish caught in sea are distributed, required for long-distance calls