CEOI, What it is...

[dragoon500ly]

The CEOI or Communications-Electronics Operating Instructions, for those who've never had the pleasure of dealing with on is the pre-SINCGARS paper "phone book" that identified what unit was to operate on what frequency, and who was allowed to use that freq during the 24-hour day.

It includes a list of all call signs and primary and secondary radio frequencies; a list of code words; an authentication table; a encryption code table; a list of passwords and challenges; and a table listing visual and sound signals.

Each CEOI was good for 30-days and each of its lists were valid for only 24-hours. SOP or standard operating procedure called for units cover by a CEOI to change pages at a specific time, usually at midnight, but I have seen 2300, 0100, 0200 hours listed as the change over time. For those stationed in Germany during the bad old days, the CEOI was to be changed every twelve hours.

CEOIs were normally issued at the Battalion/Squadron level to unit commanders, XOs and 1st Sergeants, platoon leaders and platoon sergeants who were then responsible for passing this info to their individual squad leaders/vehicle commanders. The battalion communications officer/NCO would be responsible for assembling the new CEOI each month and would also be responsible, along with a unit NCO for destroying the old CEOI, this was done by burning (CEOIs were manufactured with a treated paper that was highly flammable). Typically, the battalion maintained a set of training CEOIs and a set of "war-issue" CEOIs, needless to say, these were classified documents and kept under strict lock and key, as well as random spot checks to verify counts.

When you were issued a CEOI, you will notice a lanyard has been threaded through the top, this goes around your neck and is removed only when you turn the CEOI back into the commo section. Units had a SOP that required that the CEOI be buttoned into one of your top pockets (easier to keep track off and, most importantly, easier for someone to verify that it has been removed from your body...).

If a CEOI was lost, it was protocol that every CEOI in the unit was immediately replaced. It didn't matter if the lost booklet was found, all were replaced.

The CEOI basically allowed anyone using it to identify themselves as a valid 'user' on the radio, confirmed your ID as a 'higher' headquarters, and allowed you to give 'official' orders, you could even be requested to 'authenticate' and give the correct response, 'confirming' your ID. If you acquire an enemy CEOI, lots of fun (havoc) can be created!

If you had to abandon your vehicle/radio, you were required to change the frequency dial to a random freq, destroy any voice-security equipment and burn your copy of the CEOI.

Hope this helps!