Allows modules to define their own text groups that can be translated.
$op: Type of operation. Currently, only supports 'groups'.
Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.
function hook_locale($op = 'groups') {
switch ($op) {
case 'groups':
return array(
'custom' => t('Custom'),
);
}
}