| ASN.1 | Abstract Syntax Notation One (ASN.1) |
| FSM | ESROS Finite State Machine. |
| IP-Message | InterPersonal Message |
| ESROS | Efficient Short Remote Operation Services |
| ESROP | ESROS Protocol Engine |
| ESRO-SAP | ESROS Service Access Point. |
| MD | Management Domain |
| MH | Message Handling |
| MHS | Message Handling System |
| MS | Message Store |
| MT | Message Transfer |
| MTA | Message Transfer Agent |
| MTS | Message Transfer Service |
| SEQ_ | Sequence Module |
| TMR_ | Timer Management Module |
| TM_ | Trace Module |
| DU_ | Data Unit Management Module |