Should attributes be shared among the elements? none means that each element will have its own standalone Attrs class directly derived from ll.xist.Elements.Attrs. For dupes each attribute that is used by more than one element will be moved into its own Attrs class. For all this will be done for all attributes.

Add model information to the namespace. no doesn't add any model information. simple only adds model = False or model = True (i.e. only the information whether the element must be empty or not). fullall adds a ll.xist.sims model object to each element class. fullonce adds full model information to, but reuses model objects for elements which have the same model.