Browsing through the Staten Island, NY telephone directory of January 1940, I found that certain phone numbers were printed with a suffix J, M, R or W. What do these mean? I've marked a few of them in the image below.

The phone book itself does not define these suffixes -- I checked carefully. These letters do not seem to represent calling rate zones, as Staten Island had only two zones.

Party lines? I'm aware that up to 4 customers could share a phone number and each would get a distinctive ring so the correct party would know to pick up, but I've never known how one would call a particular party on a party line. This phone book mentions that "party lines are available" but gives no further information about them.

1940 telephone directory

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    I can't post an answer right now, but I remember being taught at college (Electronics & Communications Engineering) that party lines in the US had been given a letter suffix (-J, -M, -R or -W) corresponding to the Morse Code ring tone that would indicate which of the parties was being called. May 21, 2020 at 23:08
  • If that's so, then perhaps someone knows how to rotary-dial one of these party line numbers with a suffix. Dial all 8 numbers at once? Dial 7 numbers then wait for a second tone?
    – MTA
    May 21, 2020 at 23:21
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    And, of course, the opening sentence of the question stopped me in my tracks: "browsing through the Staten Island phone book of 1940"... :) I'm entirely sympathetic, having similar tendencies in various directions, but it did catch my fancy! :) May 22, 2020 at 2:58
  • @sempaiscuba I think the part about morse code is a red herring. The source in the answer we have now doesn't indicate it, and those four letters aren't particularly good distinctive rings (too similar to each other, and too long, especially J).
    – hobbs
    May 22, 2020 at 6:59
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    @FreeMan A lot of the old London exchange codes are alphabetic. Living in Battersea, I always thought it cool to have my very own BAT-number.
    – richardb
    May 23, 2020 at 11:42

4 Answers 4


You are correct that these are party lines. The letters represent an additional digit dialed after the others in cases where automatic operations was implemented. This article goes into great depth all about how multi-party telephone lines worked, but as a short excerpt:

A scheme widely used in the Bell Telephone System for four-party full selective lines (under both manual and automatic operation) used a suffix letter, generally from the set J, M, R, and W, to designate which of the four ringing signals applies to the station. These letters were chosen to not be easily mis-heard when spoken (with regard to manual operation).

With regard to automatic operation, in metropolitan areas, the dials had most of the letters of the alphabet associated with digit values, and through that scheme J, M, R and W were associated with the digits 5, 6, 7, and 9. In other areas, when the dials did not have the full repertoire of letters, they nevertheless had J, M, R and W on the corresponding digits.

Here is an image from such a dial:

enter image description here

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    Good find on this. May 21, 2020 at 23:25
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    The article states on Page 29 that all digits were dialed in sequence (no waiting for an additional tone), so party line subscribers had, in effect, 8-digit phone numbers.
    – MTA
    May 21, 2020 at 23:50
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    Needs to make explicit pre-automatic operator assisted use case: “customers would request a phone number of the operator including the letter suffix, the operator would then connect them” etc. Human mediated dialing is unexpected practice for moderns. May 22, 2020 at 2:52
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    @SamuelRussell was that still the case in 1940 NYC? It's not clear to me.
    – Brian Z
    May 22, 2020 at 11:27

Can't talk about New York (as I'm in Australia), but when I was a kid the Brisbane phone numbers had a one two digit alpha prefix, then a 4 digit number - eg my grandparents were J 2871, and my aunt LX 1710. These letters were merely mapped on to the dial (note that Australian phones go from 1 to 9 then zero): 1 A 2 B 3 C 4 J 7 L 6 M 7 N 8 P o X 0 Y (I think - i can't be certain of 6, 7 and 8).

Our party lines were listed by providing a suffix (a letter whose Morse Code was used as the ring for that number), eg 2028 R. I had a mate whose number was "Pony Hills 1 Z". When I was working near Sydney, I rang trunks to get connected to this number. After being summarily informed that there was no such number and that I must be joking, I stuck to my guns. It then took time to convince exchange that Pony Hills was a sub-exchange out of Injune, which was a sun-exchange out of Roma, which was 500km west of Brisbane! Yes, I finally got connected.

I realise that this is unlikely to shed any light on your question, but it reminded me of some very pleasant times in the Australian outback!

Best of luck with your telephonic peregrinations!

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    Personal experiences sometimes make for the most instructive stories!
    – gktscrk
    May 22, 2020 at 15:24
  • "Pony Hills is a rural locality in the Maranoa Region, Queensland, Australia. In the 2016 census, Pony Hills had a population of 11 people." - it's no wonder you couldn't get a dial tone.
    – Mazura
    May 25, 2020 at 4:35

Although they may have been party lines, that has nothing to do with Telephone exchange names which were used, "so that each telephone number in an area was unique."

Until 1923, a dialer would call an operator and ask for the person they wanted to reach by giving their exchange name or number. Phone numbers were just three or four digits, with an exchange name tacked onto the front. Names were sometimes selected to be memorable or easily understood over the phone. “CALUMET-555,” for example, could be taken from local Chicago geography.

The 311 On Chicago's Early Phone Numbers, wbez.org

Until recently my family owned a 100yo(? we're not sure) company that still had its original phone number prefaced with BR(unswick). We still have the sign and it's missing the zero that you'd have to tack onto the end to make it work.

Calumet is a suburb of Chicago, and '311' is how you dial information. I don't know where Brunswick is though. Likely it has something to do with where one of their offices were. "Brunswick billiard tables were a commercial success, and the business expanded and opened the first of what would become many branch offices in Chicago, Illinois, in 1848."

  • "Exchange prefixes were not necessarily based on a logical location." – forgottenchicago.com ... but the ones that made sense did.
    – Mazura
    May 25, 2020 at 4:42
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    Speaking of phone numbers getting longer over time: on page 57 of the 1940 phone directory linked in the original question is New Dorp Coal Corporation. Their original phone number was 11. Just 11. How's that for an early adopter of new technology? By 1940 they had a 7-character phone number: Dongan Hills 6-1100. They closed in 2009 as New Dorp Lumber, having retained that same phone number through the name change until the end, with a sign in their back lot that still said New Dorp Coal.
    – MTA
    May 26, 2020 at 21:12

I don't think this has much to do with the Morse code. The letter is the same as dialing the number. Look on your dial the numbers are still there. Later when the telephone number system was expanded, my number in NJ was through the Charter exchange; Ch-9-0979. C is 2 and H is 4. So you actually dialed 24-9-0979.

It is quite correct to say this was done to make it easier for the human (mostly women by this time) operator. Transylvania-6 and -7 were NYC exchanges the most famous number was Transylvania-6-5000 used in the song by that name. (See note below.) That was before my time, but I remember it was the Hotel Pennsylvania near Madison Square Garden. (Its still there!)

The dial was a mechanical interrupter so the marks and spaces were the same length, as I remember it. This worked but was slow and eventually was replaced starting in 1961 by an electronic 2-tone system.

I also remember Mulberry was the Newark, NJ exchange and my grandmothers number in East Orange, NJ through the Orange exchange was Or-2-9306.Also, in Sussex,NJ my number was Wi-8-4018 which was a four-party line from the Windsor exchange . (One of the neighbors used to listen in on other peoples calls.)

  • By the way, the NYC exchange was really Pennsylvania, that was just a joke done in 1963 by Merrie Melodies. (I think its funny.)
    – Ted Moss
    May 24, 2020 at 22:23
  • This answer reflects a misunderstanding of the earlier comment on Morse code. Private (non-party) lines had a normal ring. Party lines were usually assigned a distinctive ring pattern such as long-short-short (Morse code dash-dot-dot = “D”) or long-long-short-short (Morse code dash-dash-dot-dot = “Z”). This allowed each of the four subscribers to know if the call was intended for them or not. In any case, as another comment points out, the ring patterns implied by Morse code J, M, R and W were probably not used as ring patterns and the Morse code connection is probably apocryphal.
    – MTA
    May 25, 2020 at 13:56

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