A system and method for enabling validation of an extensible markup language (XML) document having elements associated with two or more schemata where elements of each schema may be arbitrarily nested within elements from the other schema and each set of elements remains valid within it's own schema. Elements of the second schema are transparent to the elements of the first schema when the word-processor validates the elements of the first schema. The elements of the second schema are separately validated, such that the elements of the first schema are transparent for the validation of the elements corresponding to the second schema.