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Here are more details
The local elements are the element components defined within complex types (global or
embedded in other elements) and within element groups (which are separate schema components
that define the whole batches of elements arranged in certain complex models).
The problem with local elements is that with their introduction there is no
direct relation any more between an element name and its type for the whole XML document.
For example, when in an XML document you meet, for instance, an element
<record>,
you need to look into the context where that element appears, because within the same XML document,
there may be quite another <record>
element describing absolutely different thing (e.g. the first one may be related
to a book-keeping record whereas another one may be saying something about a music song,
and the whole document is something like a sales log of a music store).
For all that trouble with their interpretation, local elements happen to be very much convenient and useful.
Now, many XML schemas are designed so that the global elements are never used in them at all.
Instead, the schema authors prefer to define only global data types and, then, refer to them from the local
element definitions, occasionally modifying some global type within the types embedded
in local elements.
All of this does not eliminate the need to know what each local element describes and to have
some documentation about it. That's especially true, because when you look at a particular XML document
described by a schema, there is no type information shown nearby each element -- only element tags and that's all.
The XSDDoc templates are designed to handle this problem in the following way:
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Those local elements that share the same name, and whose type is determined
by 'type' attribute referring to the same global simple or complex type, are considered as a single
quasi-global element.
Unlike ordinary global elements whose names are unique for the whole namespace, each quasi-global element
is unique only by its name/type combination. Almost anything that can be said about each local element
with equal name/type combination is all the same and, therefore, may be referred and documented
as a single unit.
Actually, such an approach may be even more interesting, because the same name/type combination
for a schema element is normally associated with the same thing from the real world.
When you try to understand a particular XML schema, tracking something associated
with different local elements scattered across the whole schema may be difficult.
Having a single documentation for this may quickly reveal a lot more details.
Each quasi-global element is documented separately and is referred to from every location
of the corresponding local elements. In various lists and summaries within the documentation
the quasi-global elements appear with their names extended with their types.
For example:
xs:element (type xs:narrowMaxMin)
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The local elements with the embedded type definition are truly local ones.
The presence of the embedded type means that such an element is associated with something
relevant to only this particular local context.
Each local element with embedded type is documented separately and referred to by its name
followed by the name of another element, which may contain it.
In the case, the element may be included in multiple other elements (e.g. when it was defined
within an element group that is reused in different locations) its name is extended with more
details about the embedded type, although that situation is rare.
For example, an expression
xs:all (within xs:group)
represents the element <xs:all>, whose type is embedded,
and which may appear in an XML document only as a child of
<xs:group> element.
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