A document format is a tool for sharing knowledge and, as such, should be as simple and accessible as possible in relation to the complexity of the document content itself. This remains true even when the format is based on an XML schema that is hidden from users when the document is displayed on screen. Unfortunately, while an XML schema can be simple, it can also be unnecessarily complex, bloated, convoluted and difficult to implement without specific knowledge of its features. This is true even if the on-screen documents are identical. In this case, complexity is an intentional tactic used to lock users into a vendor, as is the case with the Microsoft 365 document format. An XML schema comprises the structure, data types and rules of an XML document and is described in an XML Schema Definition (XSD) file. This tells the PC what to expect and checks that the data follows the rules. In theory, XML and XSD together form the basis of the concept of interoperability. However, in practice, an XML schema can be made so complex that it becomes a barrier rather than a bridge. An “artificially complex” XML schema goes beyond the level of complexity