| Subject | Bulgarian | English |
| comp., MS | Телефонен API интерфейс | Telephony API (An application programming interface (API) used by communications programs to work with telephony and network services) |
| comp., MS | телефонен потребителски интерфейс | Telephone User Interface (An interface that is used to navigate the menus of a Unified Messaging (UM) system using DTMF or touchtone inputs) |