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.)
Mostly used by independents rather than by the Bell System.
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.