CursusFormatPhone
This output filter formats a normalized phone number in different formats.
The input has to be formatted according to the national format in the system
setting cursus.phonenumber_country.
The options of the output filter can be set to E164, NATIONAL or
INTERNATIONAL
E164 can be used to dial the number by a href with a mobile phone.
NATIONAL uses the national format, the number belongs to.
INTERNATIONAL uses the international format.