Those aren’t codes, they are hashes. Someone is sending a message that they have something that hashes to those values. If the other guys has them and hashes, they get the same values, proving the first guys has them, or at least they have that hash.
A hash is simply a one way encryption. Think of it as adding up every character and coming up with a value. Any change to the characters changes the resulting value.
Could it actually be acknowledgement of receiving of material.
Each section from a different source. Kerry/State dept. Etc