Annex E deals with measurement uncertainty for software quality measurement in the context of ISO/IEC 17025, the standard for testing and calibration laboratory competence. The three headings are specific: general, characteristics of software quality measurements, and applicability of measurement uncertainty. That sequence suggests the annex first describes what makes a software quality measurement different, then asks when an uncertainty statement applies. It matters because a laboratory accredited to ISO/IEC 17025 that reports a software quality measure is making a statement about the competence of its measurement, not only about the product. The annex is informative and it does not turn the draft into an accreditation standard. A team outside a laboratory can still use it to think about the confidence it has in a number.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.