This clause needs more clarification. The term “structure” is used but the text implies “parsed”. An address can be syntactically (structurally) correct even if not maximally parsed.
Also it should be noted that even if a fully parsed form was presented to a common person, it could still be filled out partially or completely unparsed.
In addition, “SpecificationLevel” does not seem to capture what is being indicated.
Add text and examples to clarify what is meant by “structured”. Consider using different terminology (e.g., parsed). Consider renaming “SpecificationLevel” (e.g., StructureLevel, ParseLevel, etc.).