Phone numbers

[xfq]

Would it be useful to write an article about phone numbers? Consider it a supporting article for #692.

[xfq]

Some information:

E.164 provides a universal structure for all telephone numbers, ensuring each one is unique worldwide. The E.164 format dictates that a complete international phone number should consist of a plus sign (+), followed by a country code, a national destination code (often called an area code), and a subscriber number. The total length of an E.164 number is limited to a maximum of 15 digits.

The Anatomy of a Phone Number

1. Country Calling Codes:

These codes can be one, two, or three digits long. For example:

• +1: United States and Canada
• +44: United Kingdom
• +234: Nigeria

The initial digit of the country code often corresponds to a geographical region. For instance, codes starting with +2 are generally for African countries, while +3 and +4 are primarily for Europe.

2. Area Codes:

Within each country, the numbering plan is further broken down by area codes. These codes specify a geographic region within a country. The length and format of area codes vary significantly.

3. Final part of the phone number:

Identify a specific telephone line within a local exchange. The length of the final part also varies widely depending on the country's numbering plan.

Special Numbers

There is no universal emergency number. While many travelers are familiar with "911" from the United States and Canada, this is not the standard everywhere.

Toll-free numbers, which are free for the caller to dial, also have different formats globally. A toll-free number in one country is generally not free to call from another.

HTML

The HTML <input type="tel"> doesn't enforce any specific validation on its own. It offers a crucial advantage on mobile devices: it typically brings up a numeric keypad, making it easier for users to enter their phone number.

[r12a]

I think you'd need to provide some guidelines for content authors, and maybe developers too, if there's anything relevant.

[xfq]

Okay, I'll try to write a draft.