Note 4/20/17: Due to circumstances I have had to move my web pages here.
This is a web-based version of the "Division Field Code Training Edition No. 2".
JPEG images of the pages in this book are available at
I have tried for the most part to mimic the formatting of the original, although
there are a few places where there are noticeable differences. One common situation is
for longer phrases; the original would use smaller type and/or put the final word(s) at
the end of the previous or next line, while I allow the phrase to wrap to the next line.
Using these Pages
When you are in the process of encoding a message, the top part of the page will
look something like the following: (Note: In this example, only the navigation buttons
are active, and the message is fixed).
YJIB CERS ELPG
|O Z U Z||4144||Disapproved
||I H A M||2325||Do you
|I V N U||2663||Displine ary
||I D C M||2227||Does
|K A Z U||2949||Discretion
||L E K U||3110||– not
|I S Z R||2599||Dispatch es (No. s)
||O O F F||3880||Doing
|L O P E||3165||Dispense ing s (with)
||Y K E K||6079||Done
|D O O H||1014||Dispensed (with)
||E D S E||1167||Double ing s
The parts of the page have the following meanings:
- Message: YJIB CERS ELPG ...— This represents the telegram as it would be sent.
Since Morse code doesn't distinguish uppercase and lowercase
letters, the message is displayed in uppercase.
- Next comes the various code words (along with the code numbers and phrases) that make up
the message. The "Delete" button can be used to remove each part of the message.
- Next come a set of buttons for navigating around the various pages. These buttons appear
at the top and bottom of each page.
- Introduction — Takes you to this introductory page
- Table of Contents — This will take you to the table of contents (page 1)
- Decode Section — This will take you to the first page of the
decoding section (page 83)
- Previous Page — Take you to the previous page (43 in this example).
- Next is a textbox to display the current page number. To go to an arbitrary page,
you can enter the page number here and press the "Go" button.
- Next Page — Take you to the next page (45 in this example).
- Then is the contents of the current page. The "Add" button to the left of each phrase
will add the corresponding phrase to the end of the message. If the current page
has two columns, There is an "Add" button for each column.
Encoding a Message
The book includes an example of encoding messages on page 8-11. Here is my own example of
encoding and decoding messages.
Suppose we want to send a message: "Do you have wireless connection with group HQ"
- We can start by looking for "Do". On page 44, we IHAM for "Do you".
- Next comes "Have", with three possibilities for "Has (have)" on page 49. For better
security, we want to use all possible groups in different messages, so randomly
- If there is a potential for confusion between tenses, the entries
for "ed", "ing", etc., can be used to make it explicit.
- Note we also could have encoded "Do you have" using the
phrases "Do" and "You have".
- Going to page 75, there is no phrases for "wireless". But noting that "radio"
is a synynom, we can find XIEX on page 63 meaning "Radio communication".
- The word "With" is on page 75, with five possible groups. Again choosing randomly,
we can add HUVB to the message.
- On page 49 we find POZL meaing "group headquarters"
- Finally, go to page 17 to insert a null SUCD as the new second
group in the message
So our final message is:
So assembling the message as "Do you have radio communication with group headquarters" we could encode it
IHAM SUCD DOHA XIEX HUVB POZL
Note that if the message included proper names or other words not in the code, then
there are two options:
- If the name/word is likely to be used often, an appropriate authority can assign
it one or more of the supplment groups (pages 77-82).
- For names or words that are not likely to be repeated can be spelled out using
the entries on pages 28-31 (See the decode example below).
Decoding a Message
Suppose we receive the message:
UREP EIHJ VIJD DEFT DOHA AFPF MITR YWGF EJHX OGVR YSVS IEBZ
Take each of the code words, and look each word up in the decoding section of code book, finding:
||Front line s
||Edge s (of)
So this message is "Attack making good progress. Front line has reached north edge of Passy."
Note that the code words are constructed so that valid groups differ by at
least two letters. If a code word is incorrect and cannot be
found in the decoding section, pages 12-16 describe
procedures to fix the error and determine the correct code word.
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