There are a great many ciphers and non-verbal communication systems in our world. I think Scholes had a good idea when he developed the idea.

I have less of a problem with the written codes, as multi-factor ciphers have been used for a long, long time. The key there is having either the right knowledge or the right key to be able to operate in that code.

I think things get stretched a bit when it comes to the non-verbal codes, either by sight or by feel. The communications, as described in the narrative, were rather impossibly verbose and complex. Of course, that was probably more related to allowing the reader to know these messages rather than the specific language of the code. No one would want a recount of a string of short-hand code and then have the translation. If he had conveyed the messages in a somewhat more choppy language, I probably wouldn't have noticed as much... other than the sheer number of different languages that some of the soldiers/people knew.

It wasn't a big deal, but it did cause me to think about it a bit.