Modifications to the play during performance

The dramatic author of the drama, who contracted the performance of his work, enjoys the following rights, if the same have not been expressly renounced: 1.Of effecting in his work the alterations and corrections which he deems necessary, provided that without consent of owner of the undertaking, an essential part of the same is not altered; 2.To require that the work if handwritten, is not communicated to persons who are strangers to the theatrical performance.