This is an XML Schema definition for the Recipe example equivalent to the DTD structure definition contained in the "XML for the absolute beginner" article And the same in extended BNF notation for grammars (usually used for defining the context-free syntax of programmng languages): Recipe --> Abstract-Recipe Abstract-Recipe --> Name ( Description | empty) (Ingredients | empty) (Instructions | empty) Name --> string Description --> string Ingredients --> (Ingredient)* Ingredient --> Qty Item Qty --> '