[Exolent[jNr]]

/**
 * Look up the continent code for a given IP address.
 *
 * @note The code can be retrieved as an integer or string (2 characters).
 * @note Possible continent codes are AF, AS, EU, NA, OC, SA for 
 * Africa(1), Asia(2), Europe(3), North America(4), Oceania(5) and South America(6).
 *
 * @param ip        The IP address to look up.
 * @param result    The result of the geoip lookup. This param is optional. 
 *                  If the lookup does not succeed, the buffer is not modified.
 * @return          The result of the geoip lookup, 0 on a failed lookup.
 */
enum Continent
{
    AFRICA = 1,
    ASIA,
    EUROPE,
    NORTH_AMERICA,
    OCEANIA,
    SOUTH_AMERICA
}
native Continent:geoip_continent_code( const ip[], result[3] = "" );

I also suggest something like:

enum Continent
{
    CONTINENT_ERROR = 0,
    AFRICA,
    ASIA,
    EUROPE,
    NORTH_AMERICA,
    OCEANIA,
    SOUTH_AMERICA
}

Then when you write code for it, you can do:

new const g_szContinentNames[Continent][] =
{
    "",
    "Africa",
    "Asia",
    "Europe",
    "North America",
    "Oceania",
    "South America"
};

// ...

new szIp[32];
get_user_ip(iPlayer, szIp, 31, 1);

new Continent:iCont = geoip_continent_code(szIp);
if( iCont == CONTINENT_ERROR )
{
    client_print(client, print_chat, "You could not be found on the Earth!");
}
else
{
    client_print(client, print_chat, "You are from %s? Awesome!", g_szContinentNames[iCont]);
}

It would have more readability.