Spec for a migration (not a new feature): Replace the "Proposed Design" section with a "Migration Strategy" section covering: data migration steps, dual-write period, validation checks, cutover plan, and rollback triggers. Include a compatibility matrix showing which clients work with old vs. new systems.
Spec requiring cross-team collaboration: Add a RACI matrix (Responsible, Accountable, Consulted, Informed) as a subsection of the implementation plan. List specific deliverables per team with dependencies between them.
Spec for a prototype or spike: Shorten the format -- keep Problem Statement, Proposed Approach, and Success Criteria. Skip detailed data models and API designs. Define the spike's timebox and exit criteria (what the spike must answer).
Security-sensitive specification: Add a dedicated Security Considerations section covering: threat model, authentication/authorization changes, data encryption requirements, audit logging, and compliance implications. Name specific threats and mitigations.
Spec that supersedes a previous spec: Reference the superseded document by name and date. Summarize what changed and why the original approach is no longer viable. Keep the superseded spec available for historical context.
Very large spec (multiple systems): Split into a parent spec (problem, requirements, architecture overview) and child specs (one per subsystem with detailed design). Parent spec defines interfaces between subsystems; child specs define internal implementation.