Astrology software often presents a single polished answer even though several different systems produced it: ephemeris calculations, house/rulership rules, interpretive doctrine, and presentation logic. Stelliums records those layers separately so a later editorial revision does not pretend the underlying chart calculation changed.

Four layers to preserve

• Astronomical facts — positions, angles, motion, and calculation timestamp.
• Rules — the governed Hellenistic logic used to derive houses, sect, Lots, aspects, and timing facts.
• Interpretation — versioned prose attached to deterministic chart facts.
• Presentation — prioritization and narrative logic deciding what a reader sees first.

Why old output should remain reproducible

When a paid report or saved chart interpretation is created, the exact rule/template/interpretation versions can be preserved. Improvements can then move forward without silently changing what was previously delivered.

What versioning does not solve

Versioning does not prove that a doctrine is historically correct. It makes the system inspectable: users and editors can identify which assumptions were used, compare revisions, and keep unsupported techniques blocked until they are governed.