A take acts on the preview it showed; a setting is judged where it is stored; a kept network and a minted secret are said (hq ADR 0163)

take ends its preview with a digest and --yes names it, as the flip does; a
changed preview or an account older than the flip allows is refused. A module
the machine holds nothing for has nothing to compare, and --yes suffices. A
published port's reach is said as the machine reported it. Every secret the
module holds on the machine is listed with where it came from, and one the
mesh minted for a service whose data was found refuses unless --mint names it.

One judgement of a module's settings against its definition, in the catalogue:
settings set refuses what cannot compose or reaches nothing, naming node,
module, layer and key; Compose leaves out a module whose definition moved
under a stored setting, the envelope says so (left_out), plan and push say it
by name, and the machine is told everything else. A stray setting no longer
refuses the whole machine where it is read (issue 096).

The per-machine setting networks keeps a found network for a taken container,
on an adopted machine only; the container's declaration carries it and the
preview names it (rule 4).

internal/catalogue/declaration.go

@@ -244,12 +244,31 @@ func (r Resolution) Declaration(with Rendering) ([]map[string]any, error) {
 type Composed struct {
 	Resources []map[string]any
 	Owner     map[string]string
+	// LeftOut is every module of this machine's set that was left out of its declaration, and
+	// why (novox/hq ADR 0163, rule 6): a setting stored for it that its definition can no longer
+	// compose. Its held things are kept and its containers untouched — the machine is told so —
+	// and it is told everything else.
+	LeftOut map[string]string
+}
+
+// LeftOut is which of this machine's modules a declaration composed with these settings leaves
+// out, and why (novox/hq ADR 0163, rule 6): each whose stored settings its definition can no longer
+// compose. Empty when every module composes. The same judgement SetSettings makes before storing.
+func (r Resolution) LeftOut(settings SettingsBy, adopted bool) map[string]string {
+	out := map[string]string{}
+	for _, m := range r.Modules {
+		if err := JudgeSettings(m, settings[m.Module], adopted); err != nil {
+			out[m.Module] = err.Error()
+		}
+	}
+	return out
 }
 
 // Compose is Declaration with the owner of every resource said.
 func (r Resolution) Compose(with Rendering) (Composed, error) {
 	owner := map[string]string{}
-	resources, err := r.compose(with, owner)
+	leftOut := map[string]string{}
+	resources, err := r.compose(with, owner, leftOut)
 	if err != nil {
 		return Composed{}, err
 	}
@@ -261,7 +280,7 @@ func (r Resolution) Compose(with Rendering) (Composed, error) {
 			"sealed": with.BusMembership, "mode": "0600",
 		})
 	}
-	return Composed{Resources: resources, Owner: owner}, nil
+	return Composed{Resources: resources, Owner: owner, LeftOut: leftOut}, nil
 }
 
 // BusMembershipID names the resource carrying a machine's membership for the new bus, and
@@ -270,7 +289,25 @@ func BusMembershipID() string { return "bus-membership" }
 
 const BusMembershipPath = "/var/lib/mesh/membership-next.json"
 
-func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[string]any, error) {
+func (r Resolution) compose(with Rendering, owner map[string]string, leftOut map[string]string) ([]map[string]any, error) {
+	// **A setting is judged where it is stored, and an impossible one costs a module, not a
+	// machine** (novox/hq ADR 0163, rule 6). A definition that moved under a stored setting makes
+	// this module uncomposable; it is left out of the declaration — its held things kept, its
+	// containers untouched, the machine told so by name — and the machine is told everything else.
+	// Before placing, because a placement is a setting too.
+	left := r.LeftOut(with.Settings, with.Adopted)
+	kept := make([]Manifest, 0, len(r.Modules))
+	for _, m := range r.Modules {
+		if why, isLeft := left[m.Module]; isLeft {
+			if leftOut != nil {
+				leftOut[m.Module] = why
+			}
+			continue
+		}
+		kept = append(kept, m)
+	}
+	r.Modules = kept
+
 	// Every manifest is placed first (novox/hq ADR 0112): the maps naming where its bindings,
 	// credentials and contributions land are resolved against this node's directories, so every
 	// reader below — the binding files, the sealed secrets, the grant paths a contribution
@@ -693,6 +730,10 @@ func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[stri
 		// Which of this module's resources its preparation runs before, if it prepares anything.
 		prepareBefore := preparationTarget(m)
 
+		// Which found networks this machine's setting keeps for each of its containers (novox/hq
+		// ADR 0163, rule 4); judged above, so an invalid one is not here.
+		keptNetworks, _ := KeptNetworks(m, with.Settings[m.Module], with.Adopted)
+
 		for _, unsettled := range resources {
 			resource, err := ApplySettings(unsettled, with.Settings[m.Module])
 			if err != nil {
@@ -702,6 +743,16 @@ func (r Resolution) compose(with Rendering, owner map[string]string) ([]map[stri
 			for k, v := range resource {
 				copied[k] = v
 			}
+			if networks, keeps := keptNetworks[fmt.Sprint(copied["id"])]; keeps {
+				// The container also joins the found network the setting names, so a neighbour
+				// that resolves it there keeps resolving it. Passed to the host as its own field,
+				// which it joins after the container is made.
+				joins := make([]any, 0, len(networks))
+				for _, n := range networks {
+					joins = append(joins, n)
+				}
+				copied["networks"] = joins
+			}
 			if err := refuseSecretsInEnvironment(copied, secretFiles, m.Module); err != nil {
 				return nil, err
 			}
@@ -947,8 +998,15 @@ func (r Resolution) filtersHere() string {
 // computed for this machine, and each module's per-node exposure. The same answer whether the node
 // is adopted or converged — the one loads it as a filter, the other declares it as openings.
 func (r Resolution) Rules(with Rendering) ([]Rule, error) {
+	// A module whose settings cannot compose is left out of the declaration (novox/hq ADR 0163,
+	// rule 6), and out of the filter with it: nothing of it is declared, so nothing of it is let
+	// through.
+	left := r.LeftOut(with.Settings, with.Adopted)
 	exposure := map[string]map[int]string{}
 	for _, m := range r.Modules {
+		if _, isLeft := left[m.Module]; isLeft {
+			continue
+		}
 		e, err := Exposure(m, with.Settings[m.Module])
 		if err != nil {
 			return nil, err