| A&B |
A&B type coin collecting Box |
| Adj |
Adjustable |
| Aka |
also known as |
| Alt |
Alternative |
| AR |
Alternative
recall i.e. Timed break recall |
| Auto |
Automatic |
| BLF |
Busy lamp
field |
| BPO |
British Post
Office |
| BS |
Bellset |
| BT |
BRITISH
TELECOM |
| BTRL |
British
Telecom Research Laboratories |
| C/O |
Cut off |
| CB |
Central
Battery (System) |
| CBS |
Central
Battery Signalling |
| CCB |
Coin
collecting box |
| CCT |
Circuit |
| CCU |
Common
control unit |
| CO |
CALL OFFICE |
| CPU |
Central
processor unit |
| CSA |
CALLED SUB
ANSWERED |
| DDI |
Direct
Dialling In |
| DEL |
Direct
Exchange Line (a normal subscribers line) |
| Dept |
Department |
| DIS |
Disconnection |
| DISA |
Direct Inward
System Access |
| DP |
distribution
point |
| DS |
Dual
signalling |
| DSS |
Direct
station select |
| DT |
Dial tone |
| DTMF |
Dual Tone
Multi Frequency |
| Dual
sig |
Dual
Signalling - i.e. both loop disconnect or DTMF |
| ER |
Earth Recall |
| Exch |
Exchange/s |
| Extn |
Extension |
| FNF |
Fault not
found |
| FUW |
For use with |
| GPO |
GENERAL POST
OFFICE |
| Inst |
Instrument |
| LB |
Local Battery |
| LCD |
Liquid
Crystal Display |
| LD |
loop dial |
| LJU |
Line Jack
Unit |
| LNR |
Last Number
Redial |
| MDF |
Main
distribution frame |
| MF |
Multi
frequency |
| Mag |
Magneto
System |
| Manu |
Manufacturer |
| Mem |
Memory |
| N.T.C. |
National
Telephone Company |
| No. |
Number |
| Nos. |
Numbers |
| NU |
Number
Unobtainable |
| OH |
OVERHEAD |
| OHD |
On Hook
Dialling |
| PABX |
Private
branch exchange system |
| PB |
Push Button |
| PBX |
Private
branch exchange |
| PET |
Permanent
Engaged Tone |
| PG |
permanent
glow |
| PI |
Postal
Instruction |
| PMBX |
Private
manual exchange system |
| PO |
POST OFFICE |
| POT |
plain old
telephone |
| pps |
Pulses Per
Second |
| PST |
Plug and
socket Telephone |
| RR |
Register
Recall (Timed Break) |
| RTNR |
Ring tone no
reply |
| RWT |
Right when
tested |
| Recall |
Could be
either Earth Loop or Timed Break or both |
| S/S |
Shared
Service |
| SARCRAM |
| SC |
Self
Contained (Loop disconnect keypad) |
| SC |
Short circuit |
| SNR |
Saved Number
Redial (stores last number dialled for redial) |
| Sim |
Similar to |
| T |
Tone |
| TAMS |
Telephone
answering machines |
| TB |
Time Break |
| TBR |
Time break
recall |
| TELE |
Telephone |
| TI |
Telecom
Instruction |
| Tele |
Telephone |
| UAX |
Unit
Automatic Exchange |
| UG |
UNDERGROUND |