WordPress at a glance
filter is not described

get_user_option_(option) filter-hook . WP 2.5.0

Filters a specific user option value.

The dynamic portion of the hook name, $option, refers to the user option name.

Usage

add_filter( 'get_user_option_(option)', 'filter_function_name_7891', 10, 3 );
function filter_function_name_7891( $result, $option, $user ){
	// filter...

	return $result;
}
$result(mixed)
Value for the user's option.
$option(string)
Name of the option being retrieved.
$user(WP_User)
WP_User object of the user whose option is being retrieved.

Where the hook is called

get_user_option()
wp-includes/user.php 487
return apply_filters( "get_user_option_{$option}", $result, $option, $user );

Where the hook is used (in WP core)

Does not used.