#A.6.C:11 — SoTA‑Echoing (informative; post‑2015 alignment)

Preface node heading:a-6-c-11-sota-echoing-informative-post-2015-alignment:7923

#Content

Informative. Alignment notes; not normative requirements.

• Adopt — BCP 14 (RFC 2119 + RFC 8174) norm keyword discipline for spec language. Modern spec-writing practice treats these keywords as a disciplined modality family; A.6.C constrains where such modality belongs (D) versus where predicate-style constraints belong (A/L).
• Adopt — behavioural/session types for protocol boundaries (post‑2015 practice). Protocols as typed interactions emphasize separating safety/progress properties (L) from runtime admission (A) and from implementer obligations (D), with trace-based evidence (E).
• Adopt/Adapt — algebraic effects & handlers / effect systems. The “operation signature vs handler semantics” split mirrors “utterance substrate vs work/evidence”, preventing execution semantics from being conflated with contract surfaces.
• Adapt — ISO/IEC/IEEE 42010:2022 viewpoint discipline. Multi-view publication is treated as viewpoints governing projections; A.6.C applies this to contract talk to avoid face-level semantic forks.