diff --git a/.gitignore b/.gitignore
index 6b4352f871..345762d7e3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -44,6 +44,7 @@ memory-bank/
 
 # Root-level underscore-prefixed directories (private/draft — never commit)
 /_*/
+/_*
 
 # Draft features documentation (internal only)
 docs/new-features/
diff --git a/AGENTS.md b/AGENTS.md
index 45af3cafd7..cff6d85c3f 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -258,6 +258,15 @@ Read the nearest `AGENTS.md` and the linked deep-dive before making a non-trivia
 
 When creating _any_ validation tests or one-off logic scripts, default to `scripts/ad-hoc/` or `tests/unit/` according to your goals. Do not pollute the `/` root context.
 
+- **Root `_*` paths are private and NEVER tracked** (`_tasks/`, `_references/`, `_mono_repo/`,
+  `_ideia/`, `_cache/` and any future `_<name>`): they live on disk only, are gitignored by the
+  anchored patterns `/_*/` + `/_*`, and some are full git repositories of their own (`_tasks` →
+  private remote `_tasks_omniroute`). Never `git add` anything inside them (a plain `add` is
+  already blocked by the ignore; never use `-f`), and never "clean them up" from the main repo —
+  untracking is done with `git rm --cached` so the disk content stays. The
+  `check:tracked-artifacts` gate (pre-commit + CI) fails on ANY tracked root path starting with
+  `_`, present or future. See Hard Rule #23 for the `_tasks` specifics.
+
 ---
 
 ## Key Conventions
diff --git a/scripts/check/check-tracked-artifacts.mjs b/scripts/check/check-tracked-artifacts.mjs
index cd6dd8414f..fc8370af80 100644
--- a/scripts/check/check-tracked-artifacts.mjs
+++ b/scripts/check/check-tracked-artifacts.mjs
@@ -27,11 +27,9 @@ const FORBIDDEN_PREFIXES = [
   "node_modules/",
   ".next/",
   "coverage/",
-  "_tasks/",
-  "_references/",
-  "_mono_repo/",
-  "_ideia/",
-  "_cache/",
+  // "_" na raiz é GENÉRICO (regra abaixo em checkTrackedArtifacts): _tasks/, _references/,
+  // _mono_repo/, _ideia/, _cache/ e qualquer _<novo>/ futuro — dirs privados, alguns com
+  // repo git próprio (_tasks). Nunca rastrear nada dentro deles (Hard Rule #23).
   ".claude/worktrees/",
   "docs/superpowers/",
   ".eslintcache", // matches .eslintcache, .eslintcache-complexity, .eslintcache-probe, …
@@ -63,6 +61,13 @@ export function checkTrackedArtifacts(trackedFiles, trackedSymlinks = []) {
       violations.push(`forbidden tracked artifact: ${file}`);
       continue;
     }
+    // Regra genérica: NENHUM caminho de raiz prefixado com "_" pode ser rastreado
+    // (dir ou arquivo). Cobre _tasks, _references, _mono_repo e qualquer _<novo> futuro;
+    // paths aninhados legítimos (src/lib/_x) não são atingidos.
+    if (file.startsWith("_")) {
+      violations.push(`forbidden tracked artifact (root underscore path): ${file}`);
+      continue;
+    }
     for (const prefix of FORBIDDEN_PREFIXES) {
       if (file.startsWith(prefix)) {
         violations.push(`forbidden tracked artifact (${prefix}*): ${file}`);
diff --git a/tests/unit/build/check-tracked-artifacts.test.ts b/tests/unit/build/check-tracked-artifacts.test.ts
index 62a5ed4b52..aaeb8f4162 100644
--- a/tests/unit/build/check-tracked-artifacts.test.ts
+++ b/tests/unit/build/check-tracked-artifacts.test.ts
@@ -84,6 +84,25 @@ test("checkTrackedArtifacts: private root underscore dirs are flagged", () => {
   assert.equal(result.length, 4);
 });
 
+test("checkTrackedArtifacts: ANY future root underscore dir is flagged (generic rule)", () => {
+  const result = checkTrackedArtifacts([
+    "_nova-pasta-futura/qualquer/arquivo.md",
+    "_scratch/notes.txt",
+  ]);
+  assert.equal(result.length, 2);
+  assert.ok(result[0].includes("root underscore path"));
+});
+
+test("checkTrackedArtifacts: root underscore FILE is flagged; nested underscore paths pass", () => {
+  const flagged = checkTrackedArtifacts(["_notas-soltas.md"]);
+  assert.equal(flagged.length, 1);
+  const nested = checkTrackedArtifacts([
+    "src/lib/_internal/helper.ts",
+    "open-sse/services/_shared/util.ts",
+  ]);
+  assert.deepEqual(nested, []);
+});
+
 test("checkTrackedArtifacts: .claude/worktrees/ prefix is flagged", () => {
   const result = checkTrackedArtifacts([".claude/worktrees/fix-123/src/app.ts"]);
   assert.equal(result.length, 1);