It's rather clear and commonsensical what the genetic code is, how it is inscribed (as a sequence of nucleotides in the DNA), what it means, and most of all: how it is decoded and works.
It's less clear and agreed upon what the histone code is, how it is inscribed, what it means, and how it works. But ideas about this seem to go into some apparent direction.
What seems clear to me: The neural code is more of a temporal code, having to do with temporal frequencies, rhythmic patterns, and synchronicity (while the other two are more of spatial codes). Probably, it's a spatio-temporal code, but that's all. I completely miss a general picture of how a possible answer might look like.
What is the actual and agreed upon look on the concept of a neural code?
Side question: Which other (maybe obvious) biological codes I did not come across ("something inscribed/encrypted/encoded to be described/decrypted/decoded")?