Something that I noticed over the last months while doing design reviews is that hardly anyone documents decisions in a design. Most designs I review are physical designs, which is understandable as most IT people are technical people who could not care less about logical designs. I am perfectly fine with that, although I do recommend taking a different approach, as long as you document why you are going down a specific path.
There can be specific constraints or requirements (both technical and business related) which justify your decision, but if you don’t document these constraints or requirements chances are someone will change the design based on a false assumption and who knows what it will lead to…