diff --git a/internal/catalogue/declaration.go b/internal/catalogue/declaration.go
index 1dfede1..8ab57f3 100644
--- a/internal/catalogue/declaration.go
+++ b/internal/catalogue/declaration.go
@@ -473,9 +473,15 @@ func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[stri
 		// find each present — refusing clearly if the operator has not provided it — before it
 		// starts anything that depends on it. The mesh creates, chowns and reconciles none of it;
 		// an `access` resource says only *this path must exist, and this module reaches it*.
-		for _, a := range m.Accesses {
+		// Where each is on THIS machine is the assignment's (novox/hq issue 153): placed by id
+		// where the operator said, the definition's default otherwise, refused where neither.
+		accesses, accessPaths, err := accessesFor(m, with.Settings[m.Module])
+		if err != nil {
+			return nil, err
+		}
+		for _, a := range accesses {
 			first = append(first, map[string]any{
-				"id": AccessID(a.Path), "type": "access", "path": a.Path, "mode": a.At(),
+				"id": AccessID(a.Path), "type": "access", "path": a.Path, "mode": a.Mode,
 			})
 		}
 		for _, to := range m.SecretRequirements() {
@@ -670,6 +676,12 @@ func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[stri
 		}
 		// And where this node places the directories the module declared without a path
 		// (novox/hq ADR 0112) — resolved once per module, named by ${dir:…} from any resource.
+		// — and, on an adopted machine, where the assignment says they already are, with the
+		// owner the data already has (novox/hq issue 153). Malformed placements are refused here.
+		placed, err := Places(m, with.Settings[m.Module])
+		if err != nil {
+			return nil, err
+		}
 		dirs := dirsFor(m, with)
 		// And the machine underneath, which no binding of its own can tell it.
 		thisMachine := machineFacts(r, with.Names, with.MeshRange)
@@ -710,6 +722,12 @@ func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[stri
 			if err := dirInto(copied, dirs, m.Module); err != nil {
 				return nil, err
 			}
+			// The operator's data the same way: ${access:…} becomes where this node keeps it,
+			// and a placed directory takes the owner the assignment said (issue 153).
+			if err := accessInto(copied, accessPaths, m.Module); err != nil {
+				return nil, err
+			}
+			ownerInto(copied, placed)
 			// **After settings, and that is the whole reason it is here.** A module's file
 			// content is where a setting lands, so a placeholder may only exist once the setting
 			// has been put in — filling secrets first would look at content that is not yet what
diff --git a/internal/catalogue/dir_into.go b/internal/catalogue/dir_into.go
index ba2a4a5..3749e1a 100644
--- a/internal/catalogue/dir_into.go
+++ b/internal/catalogue/dir_into.go
@@ -67,11 +67,18 @@ func dataRoot(with Rendering) string {
 func dirsFor(m Manifest, with Rendering) map[string]string {
 	dirs := map[string]string{}
 	var beneath []map[string]any
+	// The assignment's placement wins over both (novox/hq issue 153). Refused elsewhere when
+	// malformed; here an invalid setting simply places nothing.
+	placed, _ := Places(m, with.Settings[m.Module])
 	for _, r := range m.Resources {
 		if fmt.Sprint(r["type"]) != "directory" {
 			continue
 		}
 		id := fmt.Sprint(r["id"])
+		if p, said := placed[id]; said {
+			dirs[id] = p.Path
+			continue
+		}
 		if path, stated := r["path"].(string); stated && path != "" {
 			if strings.HasPrefix(path, "${dir:") {
 				beneath = append(beneath, r)
diff --git a/internal/catalogue/manifest.go b/internal/catalogue/manifest.go
index 044620f..238a8d6 100644
--- a/internal/catalogue/manifest.go
+++ b/internal/catalogue/manifest.go
@@ -91,8 +91,13 @@ const (
 // If the path is absent when a machine applies, the host refuses clearly rather than creating it:
 // the mesh does not own it, so conjuring it would be a lie the host then acts on.
 type Access struct {
-	// Path is the absolute path on the machine, as the operator provides it.
-	Path string `json:"path"`
+	// ID is the name the module gives this access, which the assignment places
+	// (`accesses: {<id>: <path>}`, novox/hq ADR 0112, issue 153) and the module's mounts name as
+	// ${access:<id>}. The shape a definition should use: it names no path of any machine.
+	ID string `json:"id,omitempty"`
+	// Path is the absolute path on the machine. A definition carrying one names an installation;
+	// tolerated as the default the assignment may replace, for accesses declared before ids.
+	Path string `json:"path,omitempty"`
 	// Mode is "read" or "read-write". Absent narrows to read.
 	Mode string `json:"mode,omitempty"`
 }
@@ -1525,7 +1530,16 @@ func ParseManifest(raw []byte) (Manifest, error) {
 		}
 	}
 	for _, a := range m.Accesses {
-		if !strings.HasPrefix(a.Path, "/") {
+		if a.ID == "" && a.Path == "" {
+			problems = append(problems, fmt.Sprintf(
+				"%s declares an access with neither an id nor a path — an id, which the assignment places",
+				m.Module))
+		}
+		if a.ID != "" && !accessRef.MatchString("${access:"+a.ID+"}") {
+			problems = append(problems, fmt.Sprintf(
+				"%s accesses %q; an access id is lowercase letters, digits and dashes", m.Module, a.ID))
+		}
+		if a.Path != "" && !strings.HasPrefix(a.Path, "/") {
 			problems = append(problems, fmt.Sprintf(
 				"%s accesses %q, which is not an absolute path", m.Module, a.Path))
 		}
@@ -1557,6 +1571,7 @@ func ParseManifest(raw []byte) (Manifest, error) {
 	// the time it sees the mount it is being asked to create the directory, which it can do.
 	problems = append(problems, m.undeclaredMounts()...)
 	problems = append(problems, m.unknownDirRefs()...)
+	problems = append(problems, m.unknownAccessRefs()...)
 
 	for i, r := range m.Resources {
 		id, _ := r["id"].(string)
diff --git a/internal/catalogue/placement.go b/internal/catalogue/placement.go
new file mode 100644
index 0000000..6a406a2
--- /dev/null
+++ b/internal/catalogue/placement.go
@@ -0,0 +1,382 @@
+package catalogue
+
+import (
+	"fmt"
+	"regexp"
+	"sort"
+	"strings"
+)
+
+// Where a module's data is on THIS machine is the assignment's (novox/hq ADR 0112, issue 153).
+//
+// A definition names no host path. It declares the directories it owns by id, and the operator's
+// shared data it needs by id too (an `access`, ADR 0051). A node has a default layout for the
+// former — <root>/<module>/<id> — and nothing at all for the latter, because shared data is
+// wherever the operator keeps it. An adopted machine keeps its data where the predecessor put it:
+// a 40 TB library on its own pool, a configuration on a second disk. Both halves are said on the
+// assignment, validated the way `endpoints` is — an id the module does not declare is refused,
+// because a setting that reaches nothing is a mistake — and resolved here, so the host receives
+// concrete paths exactly as it always has and learns no field.
+//
+//	{"places":   {"config": "/services/sonarr/config",
+//	              "data":   {"path": "/mnt/plex/data", "owner": "1000:1000"}},
+//	 "accesses": {"series": "/storage/media/series",
+//	              "downloads": "/storage/downloads"}}
+//
+// A placed directory is still the mesh's: created, chowned to the owner the assignment says (or
+// the manifest's), removed when empty and no longer declared. A placed access is still the
+// operator's: mounted, never created, chowned or removed.
+
+// PlacesSetting is the settings key that places a module's declared directories, by id.
+const PlacesSetting = "places"
+
+// AccessesSetting is the settings key that says where a module's accesses are on this node, by id.
+const AccessesSetting = "accesses"
+
+// Placement is what an assignment says about one of a module's directories.
+type Placement struct {
+	// Path is where the directory is on this machine. Absolute.
+	Path string
+	// Owner is "uid:gid" when the assignment overrides the manifest's — the predecessor's data is
+	// owned by whoever it ran as, and that is one machine's fact.
+	Owner string
+}
+
+var ownerShape = regexp.MustCompile(`^[0-9]+:[0-9]+$`)
+
+// accessRef is how a module names one of its accesses: ${access:<id>}.
+var accessRef = regexp.MustCompile(`\$\{access:([a-z0-9][a-z0-9-]*)\}`)
+
+// Places reads where this node places the module's directories, by directory id.
+//
+// It refuses an id the module declares no directory for, a path that is not absolute, and an
+// owner that is not uid:gid. A directory the assignment does not mention keeps the manifest's
+// stated path or the node's default layout.
+func Places(m Manifest, layers []Layer) (map[string]Placement, error) {
+	declared := map[string]bool{}
+	for _, r := range m.Resources {
+		if fmt.Sprint(r["type"]) == "directory" {
+			declared[fmt.Sprint(r["id"])] = true
+		}
+	}
+	out := map[string]Placement{}
+	for _, layer := range layers {
+		raw, ok := layer.Values[PlacesSetting]
+		if !ok {
+			continue
+		}
+		blocks, ok := raw.(map[string]any)
+		if !ok {
+			return nil, fmt.Errorf("%s: %s is a { directory: path | { path, owner } } map, and %q set it to something else",
+				m.Module, PlacesSetting, layer.From)
+		}
+		for id, body := range blocks {
+			if !declared[id] {
+				return nil, fmt.Errorf(
+					"%s places the directory %q, which it does not declare — the setting reaches "+
+						"nothing. It declares %s", m.Module, id, orNothing(namesOfDirs(directoriesOf(m))))
+			}
+			p := out[id]
+			switch v := body.(type) {
+			case string:
+				p.Path = strings.TrimSpace(v)
+			case map[string]any:
+				if path, said := v["path"]; said {
+					text, _ := path.(string)
+					p.Path = strings.TrimSpace(text)
+				}
+				if owner, said := v["owner"]; said {
+					text, _ := owner.(string)
+					if !ownerShape.MatchString(strings.TrimSpace(text)) {
+						return nil, fmt.Errorf("%s places %q with owner %v; an owner is uid:gid, numeric",
+							m.Module, id, owner)
+					}
+					p.Owner = strings.TrimSpace(text)
+				}
+			default:
+				return nil, fmt.Errorf("%s places %q with %v; a placement is a path, or { path, owner }",
+					m.Module, id, body)
+			}
+			if p.Path == "" {
+				return nil, fmt.Errorf("%s places %q without a path", m.Module, id)
+			}
+			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, "/")
+			out[id] = p
+		}
+	}
+	if len(out) == 0 {
+		return nil, nil
+	}
+	return out, nil
+}
+
+// AccessPlaces reads where this node keeps the operator's data the module accesses, by access id.
+//
+// It refuses an id the module declares no access under, and a path that is not absolute. An
+// access declared by path alone cannot be placed — it has no name to place it by.
+func AccessPlaces(m Manifest, layers []Layer) (map[string]string, error) {
+	declared := map[string]bool{}
+	for _, a := range m.Accesses {
+		if a.ID != "" {
+			declared[a.ID] = true
+		}
+	}
+	out := map[string]string{}
+	for _, layer := range layers {
+		raw, ok := layer.Values[AccessesSetting]
+		if !ok {
+			continue
+		}
+		blocks, ok := raw.(map[string]any)
+		if !ok {
+			return nil, fmt.Errorf("%s: %s is a { access: path } map, and %q set it to something else",
+				m.Module, AccessesSetting, layer.From)
+		}
+		for id, body := range blocks {
+			if !declared[id] {
+				return nil, fmt.Errorf(
+					"%s places the access %q, which it does not declare — the setting reaches "+
+						"nothing. It declares %s", m.Module, id, orNothing(namesOfAccesses(m)))
+			}
+			path, _ := body.(string)
+			path = strings.TrimSpace(path)
+			if !strings.HasPrefix(path, "/") {
+				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, "/")
+		}
+	}
+	if len(out) == 0 {
+		return nil, nil
+	}
+	return out, nil
+}
+
+// placedAccess is one access with the path it resolves to on this node.
+type placedAccess struct {
+	ID   string
+	Path string
+	Mode string
+}
+
+// accessesFor is every access of a module with its path on this node: the assignment's where it
+// placed one, the definition's where it carries a default, and refused where neither says — an
+// access that resolves to nowhere would reach the machine as a mount of nothing.
+func accessesFor(m Manifest, layers []Layer) ([]placedAccess, map[string]string, error) {
+	placed, err := AccessPlaces(m, layers)
+	if err != nil {
+		return nil, nil, err
+	}
+	var out []placedAccess
+	byID := map[string]string{}
+	for _, a := range m.Accesses {
+		path := a.Path
+		if a.ID != "" {
+			if at, said := placed[a.ID]; said {
+				path = at
+			}
+		}
+		if path == "" {
+			return nil, nil, fmt.Errorf(
+				"%s accesses %q, and nothing says where that is on this node — the definition "+
+					"carries no path (it must not, novox/hq ADR 0112) and the assignment places "+
+					"none. Set %s: {%q: \"/where/it/is\"}",
+				m.Module, a.ID, AccessesSetting, a.ID)
+		}
+		out = append(out, placedAccess{ID: a.ID, Path: path, Mode: a.At()})
+		if a.ID != "" {
+			byID[a.ID] = path
+		}
+	}
+	return out, byID, nil
+}
+
+// accessFill resolves every ${access:…} in one string, or refuses a reference naming no access.
+func accessFill(s string, accesses map[string]string, module string) (string, error) {
+	var missing error
+	out := accessRef.ReplaceAllStringFunc(s, func(ref string) string {
+		id := accessRef.FindStringSubmatch(ref)[1]
+		path, has := accesses[id]
+		if !has {
+			missing = fmt.Errorf(
+				"%s says ${access:%s}, and %s declares no access %q. It declares %s",
+				module, id, module, id, orNothing(namesOfAccessIDs(accesses)))
+			return ref
+		}
+		return path
+	})
+	return out, missing
+}
+
+// accessInto fills every ${access:…} a resource carries — in its path, its content, its mounts,
+// its environment and its env-files — with the path this node resolved for it. The same walk as
+// dirInto, for the same reason: a literal `${access:x}` reaching the machine would be mounted as
+// a directory called that.
+func accessInto(resource map[string]any, accesses map[string]string, module string) error {
+	if !mentionsAccess(resource) {
+		return nil
+	}
+	fill := func(s string) (string, error) { return accessFill(s, accesses, module) }
+	var err error
+	if path, ok := resource["path"].(string); ok {
+		if resource["path"], err = fill(path); err != nil {
+			return err
+		}
+	}
+	if content, ok := resource["content"].(string); ok {
+		if resource["content"], err = fill(content); err != nil {
+			return err
+		}
+	}
+	for _, field := range []string{"volumes", "env-file"} {
+		list, ok := resource[field].([]any)
+		if !ok {
+			continue
+		}
+		filled := make([]any, len(list))
+		for i, v := range list {
+			filled[i] = v
+			if s, ok := v.(string); ok {
+				if filled[i], err = fill(s); err != nil {
+					return err
+				}
+			}
+		}
+		resource[field] = filled
+	}
+	if env, ok := resource["env"].(map[string]any); ok {
+		filled := make(map[string]any, len(env))
+		for key, v := range env {
+			filled[key] = v
+			if s, ok := v.(string); ok {
+				if filled[key], err = fill(s); err != nil {
+					return err
+				}
+			}
+		}
+		resource["env"] = filled
+	}
+	return nil
+}
+
+func mentionsAccess(resource map[string]any) bool {
+	for _, field := range []string{"path", "content"} {
+		if s, ok := resource[field].(string); ok && accessRef.MatchString(s) {
+			return true
+		}
+	}
+	for _, field := range []string{"volumes", "env-file"} {
+		if list, ok := resource[field].([]any); ok {
+			for _, v := range list {
+				if s, ok := v.(string); ok && accessRef.MatchString(s) {
+					return true
+				}
+			}
+		}
+	}
+	if env, ok := resource["env"].(map[string]any); ok {
+		for _, v := range env {
+			if s, ok := v.(string); ok && accessRef.MatchString(s) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// ownerInto gives a placed directory the owner the assignment said, where it said one. The
+// manifest's owner is what the image expects on any machine; the assignment's is what this
+// machine's data already is.
+func ownerInto(resource map[string]any, placed map[string]Placement) {
+	if fmt.Sprint(resource["type"]) != "directory" {
+		return
+	}
+	if p, ok := placed[fmt.Sprint(resource["id"])]; ok && p.Owner != "" {
+		resource["owner"] = p.Owner
+	}
+}
+
+// unknownAccessRefs is every ${access:…} in the definition that names no access the definition
+// declares by id — refused where the author is, as unknownDirRefs does for directories.
+func (m Manifest) unknownAccessRefs() []string {
+	declared := map[string]bool{}
+	for _, a := range m.Accesses {
+		if a.ID != "" {
+			declared[a.ID] = true
+		}
+	}
+	seen := map[string]bool{}
+	var problems []string
+	refuse := func(s string, where any) {
+		for _, match := range accessRef.FindAllStringSubmatch(s, -1) {
+			id := match[1]
+			if declared[id] || seen[id] {
+				continue
+			}
+			seen[id] = true
+			problems = append(problems, fmt.Sprintf(
+				"%s says ${access:%s} in %v, and declares no access %q — a reference the mesh "+
+					"cannot place would reach the machine as a literal path",
+				m.Module, id, where, id))
+		}
+	}
+	for _, r := range m.Resources {
+		for _, field := range []string{"path", "content"} {
+			if s, ok := r[field].(string); ok {
+				refuse(s, r["id"])
+			}
+		}
+		for _, field := range []string{"volumes", "env-file"} {
+			if list, ok := r[field].([]any); ok {
+				for _, v := range list {
+					if s, ok := v.(string); ok {
+						refuse(s, r["id"])
+					}
+				}
+			}
+		}
+		if env, ok := r["env"].(map[string]any); ok {
+			for _, v := range env {
+				if s, ok := v.(string); ok {
+					refuse(s, r["id"])
+				}
+			}
+		}
+	}
+	sort.Strings(problems)
+	return problems
+}
+
+func directoriesOf(m Manifest) map[string]string {
+	dirs := map[string]string{}
+	for _, r := range m.Resources {
+		if fmt.Sprint(r["type"]) == "directory" {
+			dirs[fmt.Sprint(r["id"])] = ""
+		}
+	}
+	return dirs
+}
+
+func namesOfAccesses(m Manifest) []string {
+	var names []string
+	for _, a := range m.Accesses {
+		if a.ID != "" {
+			names = append(names, fmt.Sprintf("%q", a.ID))
+		}
+	}
+	sort.Strings(names)
+	return names
+}
+
+func namesOfAccessIDs(accesses map[string]string) []string {
+	var names []string
+	for id := range accesses {
+		names = append(names, fmt.Sprintf("%q", id))
+	}
+	sort.Strings(names)
+	return names
+}
diff --git a/internal/catalogue/placement_test.go b/internal/catalogue/placement_test.go
new file mode 100644
index 0000000..8cffa5e
--- /dev/null
+++ b/internal/catalogue/placement_test.go
@@ -0,0 +1,172 @@
+package catalogue
+
+import (
+	"strings"
+	"testing"
+)
+
+// The case novox/hq issue 153 records: an adopted machine keeps its data where the predecessor put
+// it — a library on its own pool that must never move, a configuration on a second disk owned by
+// whoever the predecessor ran as. A definition may name none of that (ADR 0112); the assignment
+// says it, by the ids the definition declared, and the machine receives concrete paths as always.
+func placeable() Manifest {
+	m := mod("arr", nil, nil, nil)
+	m.Resources = []map[string]any{
+		{"id": "state", "type": "directory", "place": ".", "mode": "0700"},
+		{"id": "config", "type": "directory", "mode": "0755", "owner": "1000:1000"},
+		{"id": "server", "type": "container", "name": "arr", "image": "arr:1",
+			"volumes": []any{"${dir:config}:/config", "${access:series}:/series", "${access:spool}:/downloads:ro"},
+			"env":     map[string]any{"SPOOL": "${access:spool}"}},
+	}
+	m.Accesses = []Access{{ID: "series", Mode: AccessReadWrite}, {ID: "spool"}}
+	return m
+}
+
+func placedBy(values map[string]any) Rendering {
+	return Rendering{Settings: SettingsBy{"arr": {{From: "node anchor", Values: values}}}}
+}
+
+func TestAnAssignmentPlacesDirectoriesAndAccesses(t *testing.T) {
+	got, err := Resolve(shelf(placeable()), []string{"arr"}, workstation(), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	out, err := got.Declaration(placedBy(map[string]any{
+		PlacesSetting: map[string]any{
+			"config": map[string]any{"path": "/services/arr/config/", "owner": "1001:2000"},
+		},
+		AccessesSetting: map[string]any{
+			"series": "/storage/media/series",
+			"spool":  "/storage/downloads",
+		},
+	}))
+	if err != nil {
+		t.Fatal(err)
+	}
+	seen := map[string]map[string]any{}
+	for _, r := range out {
+		seen[r["id"].(string)] = r
+	}
+	config := seen["arr.config"]
+	if config["path"] != "/services/arr/config" || config["owner"] != "1001:2000" {
+		t.Fatalf("the placed directory is %v %v; want the assignment's path and owner", config["path"], config["owner"])
+	}
+	if seen["arr.state"]["path"] != "/var/lib/arr" {
+		t.Fatalf("an unplaced directory left the default layout: %v", seen["arr.state"]["path"])
+	}
+	var accesses []string
+	for _, r := range out {
+		if r["type"] == "access" {
+			accesses = append(accesses, r["path"].(string)+" "+r["mode"].(string))
+		}
+	}
+	if strings.Join(accesses, ",") != "/storage/media/series read-write,/storage/downloads read" {
+		t.Fatalf("the accesses reached the machine as %v", accesses)
+	}
+	server := seen["arr.server"]
+	mounts := server["volumes"].([]any)
+	if mounts[0] != "/services/arr/config:/config" || mounts[1] != "/storage/media/series:/series" ||
+		mounts[2] != "/storage/downloads:/downloads:ro" {
+		t.Fatalf("the mounts were not filled with the placed paths: %v", mounts)
+	}
+	if server["env"].(map[string]any)["SPOOL"] != "/storage/downloads" {
+		t.Fatalf("the environment was not filled: %v", server["env"])
+	}
+}
+
+// An access declared by id and placed by nobody resolves to nowhere, and that is refused with the
+// setting to write — not mounted as the literal, not skipped.
+func TestAnUnplacedAccessIsRefusedByName(t *testing.T) {
+	got, err := Resolve(shelf(placeable()), []string{"arr"}, workstation(), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	_, err = got.Declaration(placedBy(map[string]any{
+		AccessesSetting: map[string]any{"series": "/storage/media/series"},
+	}))
+	if err == nil || !strings.Contains(err.Error(), `"spool"`) || !strings.Contains(err.Error(), AccessesSetting) {
+		t.Fatalf("an access nobody placed was not refused by name: %v", err)
+	}
+}
+
+// Validated like endpoints: an id the module does not declare reaches nothing, and the refusal
+// says what it does declare; a relative path and a non-numeric owner are refused too.
+func TestPlacementsAreValidated(t *testing.T) {
+	m := placeable()
+	layers := func(values map[string]any) []Layer { return placedBy(values).Settings["arr"] }
+
+	_, err := Places(m, layers(map[string]any{PlacesSetting: map[string]any{"data": "/mnt/data"}}))
+	if err == nil || !strings.Contains(err.Error(), "does not declare") || !strings.Contains(err.Error(), `"config"`) {
+		t.Fatalf("placing an undeclared directory was accepted: %v", err)
+	}
+	_, err = Places(m, layers(map[string]any{PlacesSetting: map[string]any{"config": "services/arr"}}))
+	if err == nil || !strings.Contains(err.Error(), "absolute") {
+		t.Fatalf("a relative placement was accepted: %v", err)
+	}
+	_, err = Places(m, layers(map[string]any{PlacesSetting: map[string]any{
+		"config": map[string]any{"path": "/services/arr", "owner": "media"}}}))
+	if err == nil || !strings.Contains(err.Error(), "uid:gid") {
+		t.Fatalf("a non-numeric owner was accepted: %v", err)
+	}
+	_, err = AccessPlaces(m, layers(map[string]any{AccessesSetting: map[string]any{"movies": "/storage/media/movies"}}))
+	if err == nil || !strings.Contains(err.Error(), "does not declare") || !strings.Contains(err.Error(), `"series"`) {
+		t.Fatalf("placing an undeclared access was accepted: %v", err)
+	}
+	_, err = AccessPlaces(m, layers(map[string]any{AccessesSetting: map[string]any{"series": "media/series"}}))
+	if err == nil || !strings.Contains(err.Error(), "absolute") {
+		t.Fatalf("a relative access was accepted: %v", err)
+	}
+	// And the two keys are never stray: they are validated here, not merged into a file.
+	if stray := UnusedSettings(m, layers(map[string]any{
+		PlacesSetting:   map[string]any{"config": "/services/arr/config"},
+		AccessesSetting: map[string]any{"series": "/storage/media/series"},
+	})); len(stray) != 0 {
+		t.Fatalf("the placement keys were reported as unused: %v", stray)
+	}
+}
+
+// A definition that carries a path still works, as the default the assignment may replace — and
+// the assignment's placement wins where both say.
+func TestADefinitionsPathIsTheDefaultTheAssignmentReplaces(t *testing.T) {
+	m := placeable()
+	m.Accesses = []Access{{ID: "series", Path: "/services/media/series", Mode: AccessReadWrite}, {ID: "spool", Path: "/services/media/downloads"}}
+	got, err := Resolve(shelf(m), []string{"arr"}, workstation(), World{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	out, err := got.Declaration(placedBy(map[string]any{
+		PlacesSetting:   map[string]any{"config": "/services/arr/config"},
+		AccessesSetting: map[string]any{"series": "/storage/media/series"},
+	}))
+	if err != nil {
+		t.Fatal(err)
+	}
+	var paths []string
+	for _, r := range out {
+		if r["type"] == "access" {
+			paths = append(paths, r["path"].(string))
+		}
+	}
+	if strings.Join(paths, ",") != "/storage/media/series,/services/media/downloads" {
+		t.Fatalf("placed one, defaulted the other: got %v", paths)
+	}
+}
+
+// A reference to an access the definition does not declare is refused where the author is.
+func TestAnUnknownAccessReferenceIsRefusedAtParse(t *testing.T) {
+	_, err := ParseManifest([]byte(`{
+	  "module": "arr", "version": "1",
+	  "accesses": [{"id": "series", "mode": "read-write"}],
+	  "resources": [
+	    {"id": "state", "type": "directory", "place": ".", "mode": "0700"},
+	    {"id": "server", "type": "container", "name": "arr", "image": "arr:1",
+	     "volumes": ["${access:movies}:/movies"]}
+	  ]}`))
+	if err == nil || !strings.Contains(err.Error(), "${access:movies}") {
+		t.Fatalf("a reference to an undeclared access was accepted: %v", err)
+	}
+	_, err = ParseManifest([]byte(`{"module": "arr", "version": "1", "accesses": [{"mode": "read"}]}`))
+	if err == nil || !strings.Contains(err.Error(), "neither an id nor a path") {
+		t.Fatalf("an access with no id and no path was accepted: %v", err)
+	}
+}
diff --git a/internal/catalogue/resolve.go b/internal/catalogue/resolve.go
index b9c3786..6bda01f 100644
--- a/internal/catalogue/resolve.go
+++ b/internal/catalogue/resolve.go
@@ -791,6 +791,9 @@ func checkResources(modules []Manifest) []string {
 	// which is what lets the stack in 04-ISSUES/036 co-resolve.
 	for _, m := range modules {
 		for _, a := range m.Accesses {
+			if a.Path == "" {
+				continue // placed by the assignment; nothing to compare at registration
+			}
 			switch other := ownedPath[a.Path]; other {
 			case "":
 				// Nobody owns it — the ordinary, correct case for shared data.
diff --git a/internal/catalogue/settings.go b/internal/catalogue/settings.go
index 6ea87ce..cc418e0 100644
--- a/internal/catalogue/settings.go
+++ b/internal/catalogue/settings.go
@@ -267,6 +267,14 @@ func UnusedSettings(m Manifest, layers []Layer) []string {
 			if key == EndpointsSetting && len(m.Listens) > 0 {
 				continue
 			}
+			// `places` puts a declared directory where this machine keeps it, `accesses` says where
+			// the operator's data is (novox/hq issue 153). Validated in Places and AccessPlaces.
+			if key == PlacesSetting && len(directoriesOf(m)) > 0 {
+				continue
+			}
+			if key == AccessesSetting && len(m.Accesses) > 0 {
+				continue
+			}
 			unused = append(unused, fmt.Sprintf(
 				"%s sets %q, and %s has no file that merges it, asks for no ${setting:%s}, and "+
 					"declares no %q in what it contributes or serves",