diff --git a/go/catalogue/amqp_is_not_a_provision_test.go b/go/catalogue/amqp_is_not_a_provision_test.go
index 0b0191c..ed82b61 100644
--- a/go/catalogue/amqp_is_not_a_provision_test.go
+++ b/go/catalogue/amqp_is_not_a_provision_test.go
@@ -50,7 +50,9 @@ func TestNoCatalogueManifestNamesAmqp(t *testing.T) {
 		fset := token.NewFileSet()
 		files, _ := filepath.Glob("*.go")
 		for _, f := range files {
-			if strings.HasSuffix(f, "_test.go") {
+			// kept_until_delivered.go keeps, deprecated, the names removed while running parts still use them; the second
+			// group removes it and this exemption together.
+			if strings.HasSuffix(f, "_test.go") || f == "kept_until_delivered.go" {
 				continue
 			}
 			parsed, err := parser.ParseFile(fset, f, nil, 0)
diff --git a/go/catalogue/kept_until_delivered.go b/go/catalogue/kept_until_delivered.go
new file mode 100644
index 0000000..c5205e1
--- /dev/null
+++ b/go/catalogue/kept_until_delivered.go
@@ -0,0 +1,188 @@
+package catalogue
+
+// This file keeps, deprecated, the exported names feat/l3b-bus removed from this package while a running part still
+// uses them: an exported name is removed only after every user of it is delivered. The checker builds the running
+// node-engine's composer (mesh-host main) beside this mesh-sdk (ADR 0548 §6), and mesh-host main, mesh-delivery main
+// (the indexer's judge, the assigner's and mesh-grants' code and tests) and mesh-tools main (node-tools' tests) name
+// them. Nothing in L3's own heads uses any of them. The second group removes this file, and its exemption in
+// TestNoCatalogueManifestNamesAmqp, once mesh-host a24a1d72 and L3's mesh-delivery and mesh-tools heads run.
+
+import (
+	"fmt"
+	"slices"
+	"sort"
+	"strings"
+)
+
+// Deprecated: kept until its users are delivered (the head of this file).
+//
+// EndedControllerName is the name the ended controller had, as its module and as its seat: no manifest may name it.
+const EndedControllerName = "mesh-controller"
+
+// The kinds of a declaration that names the controller.
+//
+// Deprecated: kept until their users are delivered (the head of this file).
+const (
+	DependsRead     = "read"
+	DependsInvoke   = "invoke"
+	DependsConsume  = "consume"
+	DependsUses     = "uses"
+	DependsWaits    = "waits"
+	DependsClaims   = "claims"
+	DependsRequires = "requires"
+	DependsIs       = "is"
+)
+
+// Deprecated: kept until its users are delivered (the head of this file).
+//
+// Dependency is one declaration of a manifest that names the controller.
+type Dependency struct {
+	Module string `json:"module"`
+	// By is the account declaring it when it is not the module's own: `process <id>` or `tools <binary>`.
+	By   string `json:"by,omitempty"`
+	Kind string `json:"kind"`
+	What string `json:"what"`
+}
+
+// onController says whether a name `<owner>.<rest>` is the controller's.
+func onController(name string) bool { return strings.HasPrefix(name, EndedControllerName+".") }
+
+// invokesController says whether an invoke names a verb of the controller's seat or a tool of its module. `*` names none:
+// it is the console's grant to every tool.
+func invokesController(invoke string) bool {
+	if seat, _, ok := SeatInvoke(invoke); ok {
+		return seat == EndedControllerName
+	}
+	return onController(invoke)
+}
+
+// Deprecated: kept until its users are delivered (the head of this file).
+//
+// Dependencies are every declaration naming the controller in the manifests given, by module.
+func Dependencies(manifests map[string]Manifest) []Dependency {
+	var out []Dependency
+	add := func(module, by, kind, what string) {
+		if d := (Dependency{Module: module, By: by, Kind: kind, What: what}); !slices.Contains(out, d) {
+			out = append(out, d)
+		}
+	}
+	for name, m := range manifests {
+		if name == EndedControllerName || m.Module == EndedControllerName {
+			add(name, "", DependsIs, EndedControllerName)
+		}
+		for _, r := range m.Reads {
+			if onController(r) {
+				add(name, "", DependsRead, r)
+			}
+		}
+		for _, i := range m.Invokes {
+			if invokesController(i) {
+				add(name, "", DependsInvoke, i)
+			}
+		}
+		for _, c := range m.Consumes {
+			if onController(c) {
+				add(name, "", DependsConsume, c)
+			}
+		}
+		for _, w := range m.Waits {
+			if onController(w) {
+				add(name, "", DependsWaits, w)
+			}
+		}
+		for _, u := range m.Uses {
+			if u == EndedControllerName {
+				add(name, "", DependsUses, u)
+			}
+		}
+		for _, c := range m.Claims {
+			if c.Name == EndedControllerName {
+				add(name, "", DependsClaims, c.Name)
+			}
+		}
+		for _, r := range m.Requires {
+			if r == EndedControllerName || onController(r) {
+				add(name, "", DependsRequires, r)
+			}
+		}
+		for _, a := range m.BusAccounts() {
+			by := "process " + a.ID
+			if a.Tools {
+				by = "tools " + a.ID
+			}
+			for _, i := range a.Bus.Invokes {
+				if invokesController(i) {
+					add(name, by, DependsInvoke, i)
+				}
+			}
+		}
+	}
+	sort.Slice(out, func(i, j int) bool {
+		a, b := out[i], out[j]
+		if a.Module != b.Module {
+			return a.Module < b.Module
+		}
+		if a.Kind != b.Kind {
+			return a.Kind < b.Kind
+		}
+		if a.What != b.What {
+			return a.What < b.What
+		}
+		return a.By < b.By
+	})
+	return out
+}
+
+// Deprecated: kept until its users are delivered (the head of this file).
+//
+// ManifestRefusals is the check over a repository's manifests, by module name: one reason per declaration naming the
+// controller, none when it passes. None given fails it, since nothing read can hide a declaration.
+func ManifestRefusals(manifests map[string]Manifest) []string {
+	if len(manifests) == 0 {
+		return []string{"no manifest was read: with nothing read, nothing naming the controller can be judged absent"}
+	}
+	var out []string
+	for _, d := range Dependencies(manifests) {
+		who := d.Module
+		if d.By != "" {
+			who += " (" + d.By + ")"
+		}
+		out = append(out, fmt.Sprintf("%s declares %s %s: the controller ended by its unassignment and nothing may name it "+
+			"(ADR 0590 clause 5)", who, d.Kind, d.What))
+	}
+	return out
+}
+
+// Deprecated: a manifest says it (Manifest.CoreCredentials, CarriesCoreCredentials); kept until its users are
+// delivered (the head of this file).
+//
+// CoreCredentialModules are the modules whose own secrets are the core's credentials: the bus, mesh-provisioner and
+// its client.
+var CoreCredentialModules = []string{"mesh-provisioner", "mesh-provisioner-client", "nats"}
+
+// Deprecated: a manifest says it (Manifest.ToolRunner, IsToolRunner); kept until its users are delivered (the head
+// of this file).
+//
+// RuntimeModule is the module that is the node's tool runtime.
+const RuntimeModule = "node-tools"
+
+// Deprecated: the kept streams are the indexer's judge's; kept until its users are delivered (the head of this file).
+//
+// StreamsKeptUntilMoved are the streams declared before the check that a module keeps its data in the bus's
+// predefined forms, each allowed by name until its module moves it.
+var StreamsKeptUntilMoved = map[string][]string{
+	"brother":                    {"device-asks"},
+	"mesh-build-go":              {"toolchains-go"},
+	"mesh-build-node":            {"toolchains-node"},
+	"mesh-mail":                  {"mail", "mail-sends"},
+	"only-office":                {"convert-asks"},
+	"mesh-delivery-assigner":     {"placement"},
+	"mesh-delivery-checker":      {"checks"},
+	"mesh-delivery-forge-bridge": {"forge"},
+}
+
+// Deprecated: nothing derives it now (DerivedUpgrade reads the bus's own manifest); kept until its users are
+// delivered (the head of this file).
+//
+// FromBus is the source an older DerivedUpgrade gave the bus's policy.
+const FromBus = "the bus"