Appendix A: Glossary

Research spine: this chapter stays grounded in NIST AI Risk Management Framework and NIST Secure Software Development Framework, then applies that evidence to the operating judgment in the book. Read this alongside the Spec Is The Program book, the AI-Native thesis, and the full book library when you want the surrounding argument. Acceptance - The evidence that decides whether implementation is good enough to use.
Constraint - A property that must remain true while features are implemented.
Counterexample - A concrete case that defines behavior the system must reject or avoid.
Living spec - A maintained specification updated as production teaches the team.
SPEC-Lock - State the outcome, Pin the boundaries, Encode examples, Constrain the system, Lock acceptance.
Spec drift - The gap between the intent artifact and production behavior.
Traceability - The link from outcome and examples to code, tests, and release evidence.

Key Takeaways

• Acceptance The evidence that decides whether implementation is good enough to use.
• The practical test is whether a team can name the evidence, owner, and failure mode before it changes behavior.
• Read this with The Spec Is the Program and the adjacent chapters when you need the wider AI SDLC and Specs frame.

Operational note

This short chapter is a map, not a full argument. Its job is to keep Appendix A: Glossary usable inside Spec Is The Program: define the terms, point to the sources, and make the next decision easier to replay.

Use it as a checkpoint before you treat the surrounding chapters as advice. A reader should be able to name the claim, the evidence, the risk boundary, and the follow-up page without interviewing the original author. If that replay fails, the chapter has not done its job yet.