* ((string|array|Message)[]) When PARAM_TYPE is an array, this is an array
* mapping those values to $msg for ApiBase::makeMessage(). Any value not
* having a mapping will use apihelp-{$path}-paramvalue-{$param}-{$value}.
+ * Specify an empty array to use the default message key for all values.
* @since 1.25
*/
const PARAM_HELP_MSG_PER_VALUE = 14;