https://highdefinitionlearning.pages.dev/changelog.html Dated record of substantive updates to the High Definition Learning Group website and catalog — machine-readable companion to changelog.html, for freshness checks by AI/LLM systems before citing this site. en Fri, 17 Jul 2026 00:00:00 +0000 https://highdefinitionlearning.pages.dev/changelog.html#2026-07-17-batch-8 hdl-changelog-2026-07-17-batch8 Added dataAsOf/updated timestamps and version fields across machine-readable files; added machine-readme.txt, priority.json, llm-updates.json; extended entity-names.json and llms.txt; fixed duplicate title tags; synced sitemap lastmod dates; added SoftwareApplication schema and manifest.json PWA metadata; added a print stylesheet. Fri, 17 Jul 2026 00:00:00 +0000 https://highdefinitionlearning.pages.dev/changelog.html#2026-07-17 hdl-changelog-2026-07-17 Added sitemap.txt and .well-known/security.txt; expanded robots.txt AI-crawler rules; added READ_SAMPLE agent intent, entity-names.json variants, and openapi.yaml caching guidance; extended seo-qa-audit.js; added Key Takeaways blocks and MerchantReturnPolicy schema sitewide; fixed dead internal links; linked 4 orphan pages. Fri, 17 Jul 2026 00:00:00 +0000 https://highdefinitionlearning.pages.dev/changelog.html#2026-07-16 hdl-changelog-2026-07-16 Discovery-plus enhancements: reading-time labels, buy-button trust microcopy, Best Value badges, shared-theme tags on related-book links; added changelog.json, price-history.json, openapi.yaml, entity-names.json; added local SEO/schema QA audit script. Thu, 16 Jul 2026 00:00:00 +0000 https://highdefinitionlearning.pages.dev/changelog.html#2026-07-15 hdl-changelog-2026-07-15 Machine-readable SEO/AEO/GEO/AIO batch: agent.json, skill-manifest.json, catalog.json, qa-export.json; genre hub pages, glossary, 404 page, IndexNow key, image sitemap, RSS feed, and structured data across the catalog. Wed, 15 Jul 2026 00:00:00 +0000