Names can improve; addresses should endure
Research vocabulary becomes clearer over time. A calculator may gain a better display name and two overlapping pieces may become one stronger case study. Those are editorial improvements. They should not turn old bookmarks, citations, or search results into dead ends.
Consolidation keeps the useful page
When related Roman dodecahedron material was consolidated, the retained case-study route carried the research forward and retired addresses redirected there. The same principle protects renamed calculator pages: preserve the stable URL unless a routing change is genuinely needed.
Redirects are reader-facing evidence
A redirect says that the site remembers its earlier map. It protects links in external notes as well as internal navigation, and it makes it possible to improve a collection without pretending the former version never existed. For a source-led site, that continuity is a practical form of intellectual honesty.
What was verified
Each old form was checked against its intended new destination, while indexes, sitemap entries, and navigation labels were reconciled. The resulting Case Studies collection is clearer, but the route history remains available to the readers who arrive through an older trail.