Working with Telephone Formats
Telephone formats specify how phone numbers are formatted when users enter the numbers in phone number fields. You can have only one phone format for each country code. The phone format is applied only when users enter numbers without other formatting symbols, such as a slash (/), or dash (-).
Before users enter phone numbers, perform the following tasks:
Set the default locale. The default phone format is determined by the locale setting. For more information, see Setting Up Locales.
Define phone formats for countries that do not have a format already defined. For more information, see Specifying Phone Formats.
If a user enters a phone number from a country for which the format has not yet been specified, then the phone number might be formatted incorrectly.