libphone-utils is used to get a national number from
an international number. It is needed for incoming
calls, which give you the international number of
the caller. You probably used national numbers in your
phonebook, so without proper configuration you will
not be able to get names instead of numbers.

This configuration can be done directly in
/etc/phone-utils.conf or via dpkg-reconfig by
running: "dpkg-reconfigure libphone-util0".

You can check the values for your country on [1]
and [2] if you don't know them yourself. I don't
know of any list providing information about
national call prefixes, but you will probably
know it yourself. It is the prefix you need to
call any number in your own land. Area code is
normally only needed with a landline telephone.

Since version 0.1+git20091220-2 there is also
a phoneprefix file in the docs directory, which
is part of the upstream libphone-utils package.

 [1] http://en.wikipedia.org/wiki/List_of_country_calling_codes
 [2] http://en.wikipedia.org/wiki/List_of_international_call_prefixes

-- Sebastian Reichel <sre@debian.org>  Wed, 23 Sep 2009 05:27:00