frontmatter.Fields trims the captured value but strips nothing after a comment marker, and IsNull compares exact strings, so superseded_by: NULL # no successor is read as the literal string 'NULL # no successor' rather than the null token -- a trailing-comment form valid YAML never resolves as null; follow-up to pr-294 per reviewer (frontmatter self-describes as a line scanner, so decide: trim unquoted trailing comments or document as unsupported) takeover 2026-08-24

frontmatter.Fields trims the captured value but strips nothing after a comment marker, and IsNull compares exact strings, so superseded_by: NULL # no successor is read as the literal string 'NULL # no successor' rather than the null token -- a trailing-comment form valid YAML never resolves as null; follow-up to pr-294 per reviewer (frontmatter self-describes as a line scanner, so decide: trim unquoted trailing comments or document as unsupported) takeover 2026-08-24

Grounds

• pursued: every reader of a frontmatter value strips a trailing comment and reads a bare null as absent; a record read one way by the board and another by the verb would show it wrong