Document processing: nonsensical paragraphs (ODF 1.2 CD01)

1.4.5 has:

----b
Conforming extended producers should not use foreign elements and
attributes for features defined in the OpenDocument schema.

OpenDocument consumers should be able to parse documents that contain
attribute values not specified within the OpenDocument schema. If an
attribute which has such an undefined value has a default value, then a
conforming consumer should assume that the attribute has this value.
Otherwise, a conforming consumer should ignore the attribute.
----e

* What are "features defined in the OpenDocument schema"? the schema
defines purely syntax. Shouldn't this say "OpenDocument specification"
for the final two words?

* In para 2 the ability to "parse documents" is mentioned. Any
conformant XML processor must be able to parse documents. Is "parse"
being used in a specialised and undefined way here? (Terms and
Definitions, again, may help here).

* What are "attribute values not specified within the OpenDocument
schema"? if an id attribute has the value "id101" is that such a value?

-- I take it this paragraph is meant to concern attributes with default
values declared in the schema. As it stands though, it makes no sense.