Your party line systems sound as though they were quite complex with a relay set and indicator on the phone. Did the system prevent you from over-hearing conversatios; it sounds as though the complex switching might have done so.
There was no special relationship between the two numbers for a party line here; each line could be jumpered to any valid outlet on the final selector.
Numbering schemes here used varying numbers of digits, from 3-digits on small rural exchanges to 4, 5, or 6-digits in towns. London had 7 digit numbers, originally assigned as 3 letters plus 4 numbers, e.g. MAY 2765 (Mayfair). Five other big cities had similar schemes. The dials were slightly different to U.S. types, in that 6 was just MN, and the letter O was on the zero. The letters were dropped about 30 years ago to give more capacity. Were Austrian dials any different?
STD (Subscriber Trunk Dialling) was introduced in the late 1950s, but it was already possible in many areas to call neighboring exchanges directly with local dialling codes (e.g. 9, 91, 82).
The STD code for London was 01, those for the other five big cities 021, 031, etc. Originally they were written with the middle digit as a letter, e.g. 0L1 (051) for Liverpool.
The smaller towns were allocated codes such as 0FA6 (Falmouth) and 0BR2 (Bristol), but again the letters were dropped later to give 0326, 0272, etc.
Over the last few years there have been a lot of changes. The 3,4, and 5-digit numbers have all been made up to 6 digits, and London and a few other areas have now been given 8-digits.
The STD codes have changed as well to make room for more mobile, premium, toll-free codes etc. The recent changes were badly planned: The code/numbers for London have changed no less than three times in the last few years.
Have you implemented the new EU-wide 112 emergency number there yet? What are the Austrian codes for emergency, operator, information, and so on?
