Hi, I'm writing an XML schema for a uni assingment. I have this thing pretty much down, except for one thing. I'm referring to this document entitled "Global versus local" (http://www.xfront.com/GlobalVersusLocal.html). According to that document, and for my requirements, I can take two approaches to this. I can write things in a "Salami Slice Design" or a "Venetian Blind Design". Obviously a "which way should I design this" question comes down to how I'll be using my schema, it's purpose etc. From the URL above: "[1] The Venetian Blind design is the one to choose where your schemas require the flexibility to turn namespace exposure on or off with a simple switch, and where component reuse is important. [2] Where your task requires that you make available to instance document authors the option to use element substitution, then use the Salami Slice design." I'm not trying to ask "how do I do my assignment", my questions are: What is "namespace exposure", and why does it matter?, and, what is an "instance document" and "element substitution"? Thanks, Joseph.