diff --git a/docs/check-plan.md b/docs/check-plan.md
index 684fe7b..027bdc1 100644
--- a/docs/check-plan.md
+++ b/docs/check-plan.md
@@ -1,6 +1,15 @@
 # `tttk check` — implementation plan (validator-first)
 
-Status: **draft / not implemented.** Supersedes `docs/compile-plan.md`.
+Status: **implemented (partial).** Supersedes `docs/compile-plan.md`.
+
+Landed: `S001`/`S002`, `D001`, `R001`/`R002`/`R003`/`R005`/`R006`,
+`C001`–`C004`, `L001`/`L002`, `A001`/`A002`, with tests. The `check` command,
+`--json`/`--strict`/`--quiet`, and exit codes are live; the markdown module is
+the browser-safe one described in §4, and `readContentIndex` backs the walk.
+
+Not yet implemented: CSV data checks (`V001`–`V005`), `D002`, `R004`, and the
+reference generator + drift guard (§7.11–§7.12). The rule catalog in §5, the
+CLI surface in §6, and the resolved decisions in §10 remain the specification.
 
 ## 1. Goal