ARPEs and BRPEs oh my!

Teletype Corp had codes for everything- sometimes consistent and sometimes puzzling. 

Here are some general observations- I’m sure I have missed/muffed some. 

Bxx for M15

Fxx for M14

Lxx for M28/M35

Uxx for M32/M33

Wxx for M38

Yxx for M37

I’ve compiled some (mostly M28) at

Here’s a good example

LXD transmitter distributor

LXDB transmitter distributor Base

LXDC transmitter distributor Cover

LAXD another kind of transmitter distributor 

LBXD another kind of transmitter distributor

LCXD ……

Then there are things like

LPE non-typing perforator

LTPE typing perforator

LPR typing reperforator

LRPE non-typing reperforator

The M14 non-typing reperf was RPE

So ARPE, BRPE, etc were new models of non-typing reperfs. 

How in the world did Teletype keep track of everything before ubiquitous computers???

Cheers