[cosmicfish]

I don't think the Project would have such a code established already simply because it would be so vulnerable to either a traitorous Project member (and there will be some) or extraction through torture or other means, and it is unlikely that a suitable code phrase could wind up in Morrow training materials by accident. But it could be possible that someone involved with training could have had an interest in cryptography and slipped such a code in without ever really expecting to use it. In the desperation surrounding the fall of Prime Base, it is not inconceivable that someone could have used the code not having any better alternative. If that is the case the code should be something non-descript, so perhaps the code is already a mnemonic for something else or perhaps part of the motto.

An alternative would be to do it like a Playfair cipher using keywords like "Morrow" or actually hide the code words somewhere in the base. Or use an Ottendorf cipher that uses the Morrow Field Manual to decode. If Teams were exposed to such tools during their survival training they could readily use them here.