Here are the common telecom acronyms starting with 0-9 in the networking world.
| 1ESS | No. 1 Electronic Switching System (AT&T) |
| 1FB | Flat-rate Business line (POTS – flat rate per call fees) |
| 1PSS | No. 1 Packet Switching System (AT&T) |
| 1TF | Transmitter First Trial Feature |
| 1MB | Measured Business line (regular POTS line – per minute fees) |
| 2ASTP | 2A Signal Transfer Point |
| 2ESS | No.2 Electronic Switching System (AT&T) |
| 2W | Two-wire |
| 2WT | Two-wire Trunk |
| 2WTI | Two-wire Trunk Interface |
| 3ESS | No.3 Electronic Switching System (AT&T) |
| 3WC | Three-way Calling |
| 4ESS | No. 4 Electronic Switching System (AT&T) |
| 4GL | Fourth Generation Language |
| 4GL | Fourth Generation Language |
| 4W | Four-wire |
| 4WT | Four-wire Trunk |
| 4WTI | Four-wire Trunk Interface |
| 5ESS | No. 5 Electronic Switching System (AT&T) |
| 8(a) | Small and Disadvantaged Business Program (Small Business Administration) |
