I've gleaned from various sources, including some old Digest posts,
> that in the U.S. there were various methods employed, including up to
> 10-way party lines with the last digit of the number selecting tip or
> ring and the appropriate ringing cadence.
This is generally the case only where the equipment used was "terminal per line" as opposed to "terminal per station." In terminal per line set ups the last digit always indicated the cadence of the ringing with 10 possible combinations for both tip and ring side of the line so that it might be possible to have 5 different ringing cadences depending on what your number is e.g. the last digit of 1 on the ring side of the line you'd have a single ring, 2 two rings, 3 one long and a short, 4 one long a short and a long, and 5 being five short rings. Repeated for the remaining digits on the tip side.
In terminal per station you could have any ringing combination but it was determined at the central office (switch.)
I've also seen references
> to tuned ringers with ringing applied at a different frequency for
> each party, and to party-line numbers having an additional digit
> (coded as a letter) added the end of the regular number.
Mostly used by independents rather than by the Bell System.
When it comes to outgoing calls once DDD and CAMA had arrived, I've
> seen references to different ringer wiring combinations to enable the
> equipment to test for originating party, and also in the earlier days
> of DDD that in some places (maybe small independents?) callers had to
> dial an ID digit (e.g. 1x + NPA + number).
On two-party lines whether it was tip or ring determined whether either party would be charged and you could use AMA. With four party you used CAMA and an operator would come on the line to ask what your number was.
Independents used "ID" digit.