diff --git a/cmd/mesh-controller/modules.go b/cmd/mesh-controller/modules.go
index 9a8e3c8b..830575a3 100644
--- a/cmd/mesh-controller/modules.go
+++ b/cmd/mesh-controller/modules.go
@@ -414,6 +414,9 @@ func settingsCommand(ctx context.Context, args []string) error {
 	// word (novox/hq issue 304). Adding and changing keys needs nothing; removing one needs this.
 	replace := set.Bool("replace", false, "for set: remove the keys the new layer does not name")
 	history := set.Bool("history", false, "for show: the layers this one replaced, the latest first")
+	// Set by the settings verb on every line it composes (novox/hq ADR 0266): a verb may not change where a
+	// module's directories are placed or which of the machine's paths it reaches.
+	throughVerb := set.Bool("through-verb", false, "the line came from the settings verb: places and accesses are refused")
 	positionals, err := parseAround(set, args[1:])
 	if err != nil {
 		return err
@@ -445,6 +448,11 @@ func settingsCommand(ctx context.Context, args []string) error {
 		if err != nil {
 			return err
 		}
+		if *throughVerb {
+			if key := terminalSettingChanged(before, values); key != "" {
+				return terminalSettingRefusal(key, positionals[0], where)
+			}
+		}
 		added, changed, removed := settingsChange(before, values)
 		if len(removed) > 0 && !*replace {
 			return fmt.Errorf("%s on %s: this layer would no longer set %s. A layer is replaced whole; "+
@@ -596,6 +604,15 @@ func settingsCommand(ctx context.Context, args []string) error {
 		if len(positionals) != 1 {
 			return errors.New("settings clear <module> [--node <node>]")
 		}
+		if *throughVerb {
+			before, _, err := inv.Layer(ctx, *node, positionals[0])
+			if err != nil {
+				return err
+			}
+			if key := terminalSettingChanged(before, nil); key != "" {
+				return terminalSettingRefusal(key, positionals[0], where)
+			}
+		}
 		if err := inv.ClearSettings(ctx, *node, positionals[0]); err != nil {
 			return err
 		}
@@ -1051,3 +1068,28 @@ func declaresTools(m catalogue.Manifest) bool {
 	}
 	return false
 }
+
+// terminalSettings are the keys a verb may not change (novox/hq ADR 0266). `places` says where the node-engine
+// creates and, as root, owns a module's directories, with an owner the setting names; `accesses` says which of
+// the machine's paths are mounted into a module's container. Set through a verb, either would let any caller —
+// an agent among them — have root hand it a directory, or mount one of the machine's into a container it
+// reaches. They are the operator's, at the controller's terminal.
+var terminalSettings = []string{catalogue.PlacesSetting, catalogue.AccessesSetting}
+
+// terminalSettingChanged is the first of those keys a layer change would add, change or remove, or "".
+func terminalSettingChanged(before, after map[string]any) string {
+	for _, key := range terminalSettings {
+		was, _ := json.Marshal(before[key])
+		now, _ := json.Marshal(after[key])
+		if string(was) != string(now) {
+			return key
+		}
+	}
+	return ""
+}
+
+func terminalSettingRefusal(key, module, where string) error {
+	return terminalRefusal("%s of %s on %s is set at the controller's terminal only, never through a verb: it says "+
+		"where root creates and owns a module's directories, or which of the machine's paths reach its container, "+
+		"and whoever may call a verb includes agents (novox/hq ADR 0266). Nothing was changed", key, module, where)
+}
diff --git a/cmd/mesh-controller/seatverbs.go b/cmd/mesh-controller/seatverbs.go
index 99650fd8..cd2eff34 100644
--- a/cmd/mesh-controller/seatverbs.go
+++ b/cmd/mesh-controller/seatverbs.go
@@ -805,13 +805,16 @@ func (a *verbArguments) commandLine() ([]string, error) {
 		var argv []string
 		switch {
 		case on("clear"):
-			argv = []string{"settings", "clear", str("module")}
+			argv = []string{"settings", "clear", str("module"), "--through-verb"}
 		case str("values") != "":
 			argv = []string{"settings", "set", str("module"), str("values")}
 			// What a set removes is refused unless meant (novox/hq ADR 0217).
 			if on("replace") {
 				argv = append(argv, "--replace")
 			}
+			// Through a verb, never places or accesses (novox/hq ADR 0266): the command refuses a change to
+			// either when told the line came from a verb.
+			argv = append(argv, "--through-verb")
 		default:
 			// Neither values nor clear: the layer as it stands, which is what a caller reads before
 			// replacing it (novox/hq ADR 0217) — and with history, the layers it replaced.
@@ -1359,7 +1362,10 @@ var commandReadForms = map[string]func(rest []string) bool{
 	// `plan <node>` previews a node's declaration; it sends nothing.
 	"plan": func([]string) bool { return true },
 	// `plans` lists and `plans <id>` shows one; `plans stop|close|go` acts.
-	"plans": func(r []string) bool { return !subIn(r, "stop", "close", "go") },
+	// Judged on every word, not the first: a flag before the subcommand (`plans --json go <id>`) still acts.
+	"plans": func(r []string) bool {
+		return !slices.ContainsFunc(r, func(w string) bool { return slices.Contains(plansActs, w) })
+	},
 	// `doctor` answers the last run, `probes` and `signals` describe; `doctor run` runs.
 	"doctor":     func(r []string) bool { return flagsOnly(r) || subIn(r, "probes", "signals") },
 	"conditions": func(r []string) bool { return flagsOnly(r) || subIn(r, "list", "show", "history") },
@@ -1380,6 +1386,9 @@ var commandReadForms = map[string]func(rest []string) bool{
 	},
 }
 
+// plansActs are the `plans` subcommands that act on a walk; no other word of a plans line is one of them.
+var plansActs = []string{"go", "stop", "close", "retry"}
+
 // heldAtTheTerminal is a refusal of policy (novox/hq ADR 0266): the verb is known and served, and this line is
 // the operator's at the controller's terminal. Never read as a verb this binary is behind on.
 type heldAtTheTerminal struct{ msg string }
diff --git a/cmd/mesh-controller/seatverbs_schema_test.go b/cmd/mesh-controller/seatverbs_schema_test.go
index 176b3455..347b693e 100644
--- a/cmd/mesh-controller/seatverbs_schema_test.go
+++ b/cmd/mesh-controller/seatverbs_schema_test.go
@@ -268,8 +268,9 @@ var accountedFlags = map[string]map[string]string{
 		"self":    "set by the verb from the repository's form: a path on the forge, or a URL",
 		"dry-run": "withheld: a dry run answers only when the build ends, which a call cannot wait for; `command` reaches it",
 	},
-	"builds": {"n": "=limit"},
-	"plans":  {"n": "=limit", "what-if": "=repository"},
+	"builds":   {"n": "=limit"},
+	"plans":    {"n": "=limit", "what-if": "=repository"},
+	"settings": {"through-verb": "set by the verb on every set and clear: places and accesses are the terminal's (novox/hq ADR 0266)"},
 	// The machine's tunnel key, named as the verb's other arguments are (novox/hq ADR 0169).
 	"durations": {
 		"json": "set by the verb: the answer is data",
diff --git a/cmd/mesh-controller/seatverbs_test.go b/cmd/mesh-controller/seatverbs_test.go
index b00517a3..54a93557 100644
--- a/cmd/mesh-controller/seatverbs_test.go
+++ b/cmd/mesh-controller/seatverbs_test.go
@@ -123,11 +123,11 @@ func TestTokenIsRefusedThroughAVerb(t *testing.T) {
 // `settings` is `settings set|clear` at a shell, with the values passed inline (novox/hq issue 198).
 func TestSettingsSetsOrClearsALayer(t *testing.T) {
 	argv, err := argvFor("settings", map[string]any{"module": "dnsmasq", "values": `{"a":1}`, "node": "ace"})
-	if err != nil || strings.Join(argv, " ") != `settings set dnsmasq {"a":1} --node ace` {
+	if err != nil || strings.Join(argv, " ") != `settings set dnsmasq {"a":1} --through-verb --node ace` {
 		t.Fatalf("set on a machine: %v %v", argv, err)
 	}
 	argv, _ = argvFor("settings", map[string]any{"module": "dnsmasq", "clear": "true"})
-	if strings.Join(argv, " ") != "settings clear dnsmasq" {
+	if strings.Join(argv, " ") != "settings clear dnsmasq --through-verb" {
 		t.Fatalf("clear for the mesh: %v", argv)
 	}
 	// Neither values nor clear reads the layer as it stands (novox/hq ADR 0217): what a caller reads
@@ -369,7 +369,8 @@ func TestTheCommandVerbOnlyReads(t *testing.T) {
 		"secret recover a", "secret export a", "token issue --new x", "identity show", "broker users",
 		"api key", "licence show", "push anchor --why w", "assign novox m", "settings set m {}",
 		"settings clear m", "module add f", "module check /etc", "module forget m", "module issue m --node a",
-		"seat rename a b", "plans close p --why w", "plans go p", "doctor run", "conditions silence c --why w",
+		"seat rename a b", "plans close p --why w", "plans go p", "plans retry p", "plans stop p",
+		"plans --json go p", "plans -n 3 close p", "plans --what-if r retry p", "doctor run", "conditions silence c --why w",
 		"retire approve x", "cleanup delete x", "delivery check", "delivery go x", "bus upgrade",
 		"mirrors --record x", "mirrors --confirm", "hand-act record x --why y --cause z", "serve", "migrate",
 		"prepare", "declare x", "overlay x", "facts", "merge-gate", "check-here", "build x", "rebuild x",
diff --git a/cmd/mesh-controller/terminal_settings_test.go b/cmd/mesh-controller/terminal_settings_test.go
new file mode 100644
index 00000000..76bf5d65
--- /dev/null
+++ b/cmd/mesh-controller/terminal_settings_test.go
@@ -0,0 +1,93 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+)
+
+// Where root creates and owns a module's directories, and which of the machine's paths reach its container,
+// are the controller's terminal's alone (novox/hq ADR 0266): through the settings verb, a caller who set
+// `places` to /etc with an owner of its own would have the next send hand it /etc.
+
+func TestTheSettingsVerbMarksEverySetAndClearAsAVerbs(t *testing.T) {
+	for _, args := range []map[string]any{
+		{"module": "plex", "values": `{"places":{"data":"/etc"}}`},
+		{"module": "plex", "values": `{}`, "replace": "true", "node": "home"},
+		{"module": "plex", "clear": "true"},
+	} {
+		argv, err := argvFor("settings", args)
+		if err != nil || !strings.Contains(strings.Join(argv, " "), "--through-verb") {
+			t.Fatalf("%v: %v %v", args, argv, err)
+		}
+	}
+	// The generic verb never reaches settings set or clear at all.
+	for _, line := range []string{"settings set plex {}", "settings clear plex"} {
+		if _, err := argvFor("command", map[string]any{"command": line}); err == nil {
+			t.Fatalf("command ran %q", line)
+		}
+	}
+}
+
+func TestATerminalSettingIsChangedOnlyAtTheTerminal(t *testing.T) {
+	cases := []struct {
+		before, after map[string]any
+		want          string
+	}{
+		{nil, map[string]any{"places": map[string]any{"data": "/etc"}}, "places"},
+		{map[string]any{"accesses": map[string]any{"m": "/storage"}}, map[string]any{}, "accesses"},
+		{map[string]any{"places": map[string]any{"d": "/srv/d"}}, nil, "places"},
+		{map[string]any{"places": map[string]any{"d": "/srv/d"}, "a": 1.0},
+			map[string]any{"places": map[string]any{"d": "/srv/d"}, "a": 2.0}, ""},
+	}
+	for _, c := range cases {
+		if got := terminalSettingChanged(c.before, c.after); got != c.want {
+			t.Errorf("%v → %v: %q, want %q", c.before, c.after, got, c.want)
+		}
+	}
+}
+
+// Over the real stores: the verb's line is refused for places, the terminal's is taken, and a clear through
+// the verb of a layer that places a directory is refused too.
+func TestPlacesAreRefusedThroughTheVerbAndTakenAtTheTerminal(t *testing.T) {
+	open := aMesh(t)
+	ctx := t.Context()
+	register(t, open, catalogue.Manifest{Module: "notes", Version: "1",
+		Resources: []map[string]any{{"id": "data", "type": "directory", "mode": "0755"},
+			{"id": "rc", "type": "file", "path": "/etc/notes.conf", "mode": "0644", "content": "x = ${setting:x}\n"}}})
+	if _, err := assign(ctx, open, "laptop", "notes"); err != nil {
+		t.Fatal(err)
+	}
+	set := func(through bool, values string) error {
+		args := []string{"set", "notes", values, "--node", "laptop"}
+		if through {
+			args = append(args, "--through-verb")
+		}
+		return settingsCommand(ctx, args)
+	}
+	if err := set(true, `{"places":{"data":{"path":"/srv/notes","owner":"1000:1000"}}}`); err == nil ||
+		!strings.Contains(err.Error(), "controller's terminal only") {
+		t.Fatalf("places through the verb: %v", err)
+	}
+	if err := set(false, `{"places":{"data":{"path":"/srv/notes","owner":"1000:1000"}},"x":0}`); err != nil {
+		t.Fatalf("places at the terminal: %v", err)
+	}
+	if err := set(true, `{"places":{"data":{"path":"/srv/notes","owner":"1000:1000"}},"x":1}`); err != nil {
+		t.Fatalf("a verb may change another key and keep places as they are: %v", err)
+	}
+	if err := settingsCommand(ctx, []string{"clear", "notes", "--node", "laptop", "--through-verb"}); err == nil ||
+		!strings.Contains(err.Error(), "controller's terminal only") {
+		t.Fatalf("a clear through the verb took places away: %v", err)
+	}
+	// And never at /etc, from anywhere.
+	if err := set(false, `{"places":{"data":{"path":"/etc","owner":"1000:1000"}},"x":1}`); err == nil ||
+		!strings.Contains(err.Error(), "/etc") {
+		t.Fatalf("a place at /etc: %v", err)
+	}
+	// A line break in any setting is refused where it is kept.
+	if err := set(false, `{"places":{"data":{"path":"/srv/notes","owner":"1000:1000"}},"x":"a\nPATH=/tmp"}`); err == nil ||
+		!strings.Contains(err.Error(), "line break") {
+		t.Fatalf("a line break: %v", err)
+	}
+}
diff --git a/cmd/mesh-controller/unseen_test.go b/cmd/mesh-controller/unseen_test.go
index 32f9ddfd..879b826b 100644
--- a/cmd/mesh-controller/unseen_test.go
+++ b/cmd/mesh-controller/unseen_test.go
@@ -158,7 +158,7 @@ func TestTheVerbsCarryReadReplaceAndMove(t *testing.T) {
 	}{
 		{"settings", map[string]any{"module": "plex", "node": "home"}, []string{"settings", "show", "plex", "--node", "home"}},
 		{"settings", map[string]any{"module": "plex", "history": "true"}, []string{"settings", "show", "plex", "--history"}},
-		{"settings", map[string]any{"module": "plex", "values": "{}", "replace": "true"}, []string{"settings", "set", "plex", "{}", "--replace"}},
+		{"settings", map[string]any{"module": "plex", "values": "{}", "replace": "true"}, []string{"settings", "set", "plex", "{}", "--replace", "--through-verb"}},
 		{"push", map[string]any{"node": "home", "move": "plex", "why": "w"},
 			[]string{"push", "home", "--wait", "0", "--move", "plex", "--why", "w"}},
 		{"push", map[string]any{"why": "w"}, []string{"push", "--behind", "--wait", "0", "--why", "w"}},
diff --git a/internal/catalogue/agent_account_test.go b/internal/catalogue/agent_account_test.go
index 70b18b26..8aad7abf 100644
--- a/internal/catalogue/agent_account_test.go
+++ b/internal/catalogue/agent_account_test.go
@@ -1,6 +1,7 @@
 package catalogue
 
 import (
+	"strings"
 	"testing"
 )
 
@@ -111,3 +112,46 @@ func TestTheRuntimeIsToldTheAgentAccount(t *testing.T) {
 		t.Error("a bundle may tell the runtime whom agents run as")
 	}
 }
+
+// No placement and no access at the machine's own system or the mesh's state, however it is spelled (novox/hq
+// ADR 0266); a module's own place elsewhere is taken.
+func TestAPlacementOrAnAccessAtTheMachinesOwnIsRefused(t *testing.T) {
+	m := Manifest{Module: "notes", Resources: []map[string]any{{"id": "data", "type": "directory"}},
+		Accesses: []Access{{ID: "media"}}}
+	for _, path := range []string{"/", "/etc", "/etc/sudoers.d", "/usr/bin", "/root", "/var/lib", "/home",
+		"/var/lib/mesh/x", "/var/lib/mesh-host", "/srv/../etc", "/proc/1", "/dev"} {
+		layers := []Layer{{From: "laptop", Values: map[string]any{PlacesSetting: map[string]any{"data": path}}}}
+		if _, err := Places(m, layers); err == nil {
+			t.Errorf("a place at %s was taken", path)
+		}
+		layers = []Layer{{From: "laptop", Values: map[string]any{AccessesSetting: map[string]any{"media": path}}}}
+		if _, err := AccessPlaces(m, layers); err == nil {
+			t.Errorf("an access at %s was taken", path)
+		}
+	}
+	for _, path := range []string{"/srv/notes", "/mnt/plex/data", "/storage/media", "/home/restic", "/var/lib/notes/data"} {
+		layers := []Layer{{From: "laptop", Values: map[string]any{PlacesSetting: map[string]any{"data": path}}}}
+		if got, err := Places(m, layers); err != nil || got["data"].Path != path {
+			t.Errorf("a place at %s: %v %v", path, got, err)
+		}
+	}
+}
+
+// A line break or a NUL in any string of any setting is refused, at any depth; PEM blocks alone may hold lines.
+func TestASettingHoldsOneLine(t *testing.T) {
+	m := Manifest{Module: "mailu"}
+	for _, v := range []any{"a\nDEBUG=1", "a\rb", "a\x00b", map[string]any{"k": []any{"ok", "x\ny"}},
+		map[string]any{"k\nx": "v"}} {
+		if err := JudgeSettings(m, []Layer{{From: "home", Values: map[string]any{"v": v}}}, false); err == nil ||
+			!strings.Contains(err.Error(), "line break") {
+			t.Errorf("%q: %v", v, err)
+		}
+	}
+	pem := "-----BEGIN CERTIFICATE-----\nMIIBeDCCAR2gAwIBAgIQ\n-----END CERTIFICATE-----\n"
+	if err := JudgeSettings(m, []Layer{{From: "home", Values: map[string]any{"root": pem}}}, false); err != nil {
+		t.Errorf("a PEM block: %v", err)
+	}
+	if err := JudgeSettings(m, []Layer{{From: "home", Values: map[string]any{"root": pem + "PATH=/tmp evil\n"}}}, false); err == nil {
+		t.Error("a PEM block with a line of something else after it was taken")
+	}
+}
diff --git a/internal/catalogue/placement.go b/internal/catalogue/placement.go
index 6a406a26..d54e07a7 100644
--- a/internal/catalogue/placement.go
+++ b/internal/catalogue/placement.go
@@ -2,6 +2,7 @@ package catalogue
 
 import (
 	"fmt"
+	"path/filepath"
 	"regexp"
 	"sort"
 	"strings"
@@ -44,6 +45,33 @@ type Placement struct {
 
 var ownerShape = regexp.MustCompile(`^[0-9]+:[0-9]+$`)
 
+// systemTrees are where no placement and no access may be: the machine's own system, and the node-engine's
+// and the tool runner's state (novox/hq ADR 0266). A placed directory is created and chowned by the
+// node-engine as root, and an access is mounted into a container: a place at /etc, owned by an account a
+// caller names, hands that account the machine. Refused at or below each of these.
+var systemTrees = []string{"/etc", "/usr", "/boot", "/root", "/proc", "/sys", "/dev", "/run", "/bin", "/sbin",
+	"/lib", "/lib64", "/var/lib/mesh", "/var/lib/mesh-host", "/var/lib/mesh-bus-conf"}
+
+// systemRoots are directories a placement may be below but never be: each holds the whole machine's, or
+// every module's or every person's, directories.
+var systemRoots = []string{"/", "/var", "/var/lib", "/home", "/mnt", "/srv", "/opt", "/storage", "/data", "/tmp", "/var/tmp"}
+
+// systemPath says why a path is the machine's own and no placement's, or "".
+func systemPath(path string) string {
+	clean := filepath.Clean(path)
+	for _, root := range systemRoots {
+		if clean == root {
+			return clean + " is a whole tree of the machine's"
+		}
+	}
+	for _, tree := range systemTrees {
+		if clean == tree || strings.HasPrefix(clean, tree+"/") {
+			return clean + " is in " + tree + ", the machine's own or the mesh's state"
+		}
+	}
+	return ""
+}
+
 // accessRef is how a module names one of its accesses: ${access:<id>}.
 var accessRef = regexp.MustCompile(`\$\{access:([a-z0-9][a-z0-9-]*)\}`)
 
@@ -103,7 +131,11 @@ func Places(m Manifest, layers []Layer) (map[string]Placement, error) {
 			if !strings.HasPrefix(p.Path, "/") {
 				return nil, fmt.Errorf("%s places %q at %q, which is not an absolute path", m.Module, id, p.Path)
 			}
-			p.Path = strings.TrimRight(p.Path, "/")
+			p.Path = filepath.Clean(p.Path)
+			if why := systemPath(p.Path); why != "" {
+				return nil, fmt.Errorf("%s places %q at %s: %s, and the node-engine would create and own it as "+
+					"root (novox/hq ADR 0266)", m.Module, id, p.Path, why)
+			}
 			out[id] = p
 		}
 	}
@@ -147,7 +179,12 @@ func AccessPlaces(m Manifest, layers []Layer) (map[string]string, error) {
 				return nil, fmt.Errorf("%s places the access %q at %v, which is not an absolute path",
 					m.Module, id, body)
 			}
-			out[id] = strings.TrimRight(path, "/")
+			path = filepath.Clean(path)
+			if why := systemPath(path); why != "" {
+				return nil, fmt.Errorf("%s places the access %q at %s: %s, and an access is mounted into the "+
+					"module's container (novox/hq ADR 0266)", m.Module, id, path, why)
+			}
+			out[id] = path
 		}
 	}
 	if len(out) == 0 {
diff --git a/internal/catalogue/settings.go b/internal/catalogue/settings.go
index d7ff5f8b..87b67bae 100644
--- a/internal/catalogue/settings.go
+++ b/internal/catalogue/settings.go
@@ -209,6 +209,68 @@ func deepCopy(in map[string]any) map[string]any {
 	return out
 }
 
+// settingsHoldOneLine refuses a line break or a NUL in any string of any setting, for every module, at any
+// depth: a key or a value, in an object or a list (novox/hq ADR 0266). A value is substituted into env and
+// configuration files the node-engine writes as root (an app's .env, a logind drop-in), and a line break
+// there is a directive of the caller's own; a NUL ends a string early wherever C reads it. Judged where a
+// setting is kept and again where it is composed, so a stored value with one costs its module its place
+// and says which key. One shape is let through: PEM blocks alone (a certificate authority's root handed to a
+// provider), whose lines are base64 between BEGIN and END. Anything else that must hold lines is the
+// module's own file, not a setting.
+func settingsHoldOneLine(module string, layers []Layer) error {
+	for _, layer := range layers {
+		for _, key := range sortedKeysAny(layer.Values) {
+			if at := lineBreakIn(layer.Values[key], key); at != "" {
+				return fmt.Errorf("%s: the setting %s in %q holds a line break or a NUL, which a file it is written "+
+					"into would read as a directive of its own (novox/hq ADR 0266); a setting is one line",
+					module, at, layer.From)
+			}
+		}
+	}
+	return nil
+}
+
+// pemShape is the one value with lines a setting may hold: PEM blocks and nothing else — a certificate
+// authority's root the operator hands a provider is one. Its lines are base64 between BEGIN and END: no
+// space, quote, dot or underscore, so no path, option or command — at most a padded line an env file would
+// read as an empty assignment, which names no program.
+var pemShape = regexp.MustCompile(`^(-----BEGIN [A-Z0-9 ]+-----\n([A-Za-z0-9+/]{1,76}={0,2}\n)+-----END [A-Z0-9 ]+-----\n?)+$`)
+
+// lineBreakIn is the path of the first string under v holding \n, \r or NUL, or "".
+func lineBreakIn(v any, at string) string {
+	switch t := v.(type) {
+	case string:
+		if strings.ContainsAny(t, "\n\r\x00") && !pemShape.MatchString(t) {
+			return at
+		}
+	case map[string]any:
+		for _, k := range sortedKeysAny(t) {
+			if strings.ContainsAny(k, "\n\r\x00") {
+				return at + "." + strings.ToValidUTF8(strings.NewReplacer("\n", "\\n", "\r", "\\r", "\x00", "\\0").Replace(k), "?")
+			}
+			if found := lineBreakIn(t[k], at+"."+k); found != "" {
+				return found
+			}
+		}
+	case []any:
+		for i, e := range t {
+			if found := lineBreakIn(e, fmt.Sprintf("%s[%d]", at, i)); found != "" {
+				return found
+			}
+		}
+	}
+	return ""
+}
+
+func sortedKeysAny(m map[string]any) []string {
+	out := make([]string, 0, len(m))
+	for k := range m {
+		out = append(out, k)
+	}
+	sort.Strings(out)
+	return out
+}
+
 // UnusedSettings names settings that reach nothing.
 //
 // Somebody who sets a key on a module with nothing mergeable, or misspells one, has changed
@@ -405,6 +467,9 @@ var networkName = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9_.-]*$`)
 // refused where it is stored (SetSettings, with UnusedSettings) and said where a plan is read,
 // and never costs a module its place.
 func JudgeSettings(m Manifest, layers []Layer, adopted bool) error {
+	if err := settingsHoldOneLine(m.Module, layers); err != nil {
+		return err
+	}
 	// With no layers too: a definition may ask for a setting nobody made — an access placed by
 	// nobody, a file's ${setting:…} nothing sets — and that is the same statement, missing.
 	if _, err := GivenPorts(m, layers); err != nil {