Hello, Following this tutorial (http://www.liquid-technologies.com/Tutorials/XmlSchemas/XsdTutorial_04.aspx -- don't worry, I use Oxygen ;-) ) I've refactored my 733 line schema into 16 separate files or sub-schemas, each with its own namespace. Now the top level schema is just 77 lines. The plan is to use these sub-schema's to build other top-level schemas. The problem is that most top level schema's are quite similar and only differ in a few low level details. For example while one top level schema supports all PaymentMethodType's (see tutorial) another top-level schema may support only VISA and MasterCard. Currently my method of creating top-level schemas involves considerable duplication. For example, my current method of creating a top-level schema in which only VISA and MasterCard are supported would involve duplicating Main.xsd and OrderType.xsd, but customizing CommonTypes.xsd and reuse CustomerTypes.xsd. (As my actual schema is a lot longer a lot more duplication is involved.) I find this duplication unacceptable primarily because it introduces a maintenance challenge i.e. I would have to maintain any number of identical sub-schemas with different names. What I would like to know is if there is a method of automatically generating a schema without via a config file of some sort (XSLT perhaps?), in order to avoid duplicating sub-schemas. Also, is it good practice for all the sub-schemas to declare the same target namespace in this case (just like the xml schema namespace xs, but have custom sub-schemas declare a separate namespace? - Olumide