Conformance clause 2.2.1 D, D3 - w or w/o namespace the same?

2.2.1 D) D.3) reads:

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If a style:condition, table:condition, table:expression, table:formula or text:formula attribute value begins with a namespace prefix bound to namespace
"urn:oasis:names:tc:opendocument:xmlns:of:1.2," the syntax and semantics of the attribute value portions that are expressions determined by the prefix shall conform to part 2 of this specification. If a namespace prefix is omitted at the beginning of the attribute value, the attribute value portions that are expressions determined by a prefix shall conform as if there were a prefix bound to namespace "urn:oasis:names:tc:opendocument:xmlns:of:1.2".

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It looks to me like with or without an explicit namespace prefix, the namespace is the same? Yes?

If that is the case, why not just say absent a namespace, then ... the namespace?

If a namespace is declared (should?) then we should say that.

It's not clear what is meant.