I've come back to this thread in search of a new theory. I liked the
M = modular idea but I've saw a new ebay listing with pictures of two
"hard-wired" WE 1500s that have number cards with the M stamp.
After much scanning, measuring, image enlarging, and font matching
I've finished making replica number cards for my own WE phones and I'm
not sure I want the M on mine anyway but I'm still curious what it
In article <email@example.com>, Allen Newman
> That's a pretty good guess. I saw a touch-tone wall phone that's
> still hard-wired (non modular) where Ma Bell put it and still has its
> original number card (this one happens to be a card, not a sticker),
> and sure enough there's no M on it. This phone is in Northwestern
> Bell territory and was probably installed between 1967 and 1969 based
> on it being touch-tone and not having the 1969-present Bell logo on
> If it stands for Modular, I wonder if it's sort of a disclaimer, since
> the reality of a modular phone is that it's far easier to move it,
> therefore there's more of a chance that the number card/sticker could
> be wrong if the customer connected the phone to a different line.
> I don't think all telcos used the M, though. I'm seeing the non-M
> layout on some modular phones on ebay.
> In article <firstname.lastname@example.org>, email@example.com
>> Allen Newman wrote:
>>> On the number cards/labels affixed to latter-decades' Bell System
>>> phones, there was a letter M stamped like this:
>> Could it have meant "modular" since that number card was intended for
>> modular phones installed by the customer? They used to give them out
>> at Phone Center stores.
>> I didn't care for them since it was a sticker, not a card. Admittedly,
>> for most people that what was best. However, since I knew how to open
>> a dial, I wanted a card to mount behind it and didn't want some sticker
>> fouling my dial. Also, they used a stamper that was in relatively
>> small type size compared to the bigger size used by traditional
>> installers. Of course all they had was all-number, no letters. In our
>> area, we were still using letters in a limited manner. To this day,
>> the official internal identifier for telephone districts in our area
>> was the old exchange name from way back.