| Subject | English | French |
| IT, tech. | A layer in the Application Layer that provides MTS Message Transfer System service elements.These services are provided by means of the services of the layer below plus the functionality of the entities in the layer,namely the MTAEs Message Transfer Agent Entity and the SDEs Submission and Delivery Entity. | Couche de transfer de message |
| agric. | fish below the acoustic layer | poisson évoluant en deçà du seuil acoustique |
| gen. | the layer below | la couche inférieure |