I wasn`t going to post here but I have been having a go at breaking this code and have had some interesting results,sadly I haven`t got the foolscap sized piece of paper that I was using to help me. After trying a few things including the numerical difference between the original letters,backwards,moving one space back etc etc I did,I seem to recall(without proof it is hard to post here) that the first four letters that I came up with that followed the same reasoning exactly when breaking the code were..... C.O.D.E.. I`ll maybe try and get some more letters one day,if I find my piece of wretched paper again.
I`m not one hundred percent sure about my results,look really as far as I know now the letters were just random scribble, but I do recall that my methods were logical.
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Responds to stimuli, tries to communicate verbally, follows limited commands, laughs or cries in interaction with loved ones.