How a developer's frontmatter block grew organically across four origins and nine fields

A developer tracing the history of their Markdown frontmatter found that none of its nine metadata fields were centrally designed — each emerged from a different project, template, or automated hook between August and September. The fields originated in four distinct places, spread through separate mechanisms including scaffolds, sync scripts, and session-closing hooks. Gaps in adoption revealed silent failures: a regex bug swallowed start-date fields in 254 of 260 sessions, and a two-field classification system was never read by any script despite being defined as 'metadata'. By contrast, four note-identifying fields enforced their own presence by breaking the build when missing, ensuring they stayed accurate and in use. The author concludes that a metadata field survives not by design intent but by whether something or someone still reads it.