From 92baf85b10796be060b86e7303a3b3f332e7adbf Mon Sep 17 00:00:00 2001
From: alvrs <alvarius@lattice.xyz>
Date: Fri, 19 Jan 2024 18:52:43 +0000
Subject: [PATCH 1/9] feat(world): prevent invalid namespace strings

---
 packages/world/src/IWorldErrors.sol     |  6 ++++++
 packages/world/src/WorldResourceId.sol  |  1 +
 packages/world/src/requireNamespace.sol | 19 ++++++++++++++++++-
 packages/world/test/World.t.sol         |  6 ++++++
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/packages/world/src/IWorldErrors.sol b/packages/world/src/IWorldErrors.sol
index 29aed90045..7308db3d23 100644
--- a/packages/world/src/IWorldErrors.sol
+++ b/packages/world/src/IWorldErrors.sol
@@ -42,6 +42,12 @@ interface IWorldErrors {
    */
   error World_InvalidResourceId(ResourceId resourceId, string resourceIdString);
 
+  /**
+   * @notice Raised when an namespace contains an invalid sequence of characters ("__").
+   * @param namespace The invalid namespace.
+   */
+  error World_InvalidNamespace(bytes14 namespace);
+
   /**
    * @notice Raised when trying to register a system that already exists.
    * @param system The address of the system.
diff --git a/packages/world/src/WorldResourceId.sol b/packages/world/src/WorldResourceId.sol
index 4c6b340103..eb91ddd245 100644
--- a/packages/world/src/WorldResourceId.sol
+++ b/packages/world/src/WorldResourceId.sol
@@ -7,6 +7,7 @@ import { ResourceId, ResourceIdInstance, TYPE_BITS } from "@latticexyz/store/src
 import { ROOT_NAMESPACE, ROOT_NAME } from "./constants.sol";
 import { RESOURCE_NAMESPACE, MASK_RESOURCE_NAMESPACE } from "./worldResourceTypes.sol";
 
+uint256 constant NAMESPACE_BYTES = 14;
 uint256 constant NAMESPACE_BITS = 14 * 8; // 14 bytes * 8 bits per byte
 uint256 constant NAME_BITS = 16 * 8; // 16 bytes * 8 bits per byte
 
diff --git a/packages/world/src/requireNamespace.sol b/packages/world/src/requireNamespace.sol
index 7de2c8088c..dd5e78c361 100644
--- a/packages/world/src/requireNamespace.sol
+++ b/packages/world/src/requireNamespace.sol
@@ -1,7 +1,9 @@
 // SPDX-License-Identifier: MIT
 pragma solidity >=0.8.21;
 
-import { ResourceId, WorldResourceIdInstance } from "./WorldResourceId.sol";
+import { Bytes } from "@latticexyz/store/src/Bytes.sol";
+
+import { ResourceId, WorldResourceIdInstance, NAMESPACE_BYTES } from "./WorldResourceId.sol";
 import { RESOURCE_NAMESPACE } from "./worldResourceTypes.sol";
 import { IWorldErrors } from "./IWorldErrors.sol";
 
@@ -13,7 +15,22 @@ using WorldResourceIdInstance for ResourceId;
  * @param resourceId The resource ID to verify.
  */
 function requireNamespace(ResourceId resourceId) pure {
+  requireValidCharacters(resourceId.getNamespace());
+
   if (ResourceId.unwrap(resourceId) != ResourceId.unwrap(resourceId.getNamespaceId())) {
     revert IWorldErrors.World_InvalidResourceType(RESOURCE_NAMESPACE, resourceId, resourceId.toString());
   }
 }
+
+/**
+ * @notice Checks if a given namespace string is valid.
+ * @dev Reverts with IWorldErrors.World_InvalidNamespace if the namespace includes the reserved separator string ("__").
+ * @param namespace The namespace to verify.
+ */
+function requireValidCharacters(bytes14 namespace) pure {
+  for (uint256 i; i < NAMESPACE_BYTES - 1; i++) {
+    if (Bytes.slice1(namespace, i) == bytes1("_") && Bytes.slice1(namespace, i + 1) == bytes1("_")) {
+      revert IWorldErrors.World_InvalidNamespace(namespace);
+    }
+  }
+}
diff --git a/packages/world/test/World.t.sol b/packages/world/test/World.t.sol
index 9078a01e79..9090eca6e6 100644
--- a/packages/world/test/World.t.sol
+++ b/packages/world/test/World.t.sol
@@ -348,6 +348,12 @@ contract WorldTest is Test, GasReporter {
     world.registerNamespace(namespaceId);
   }
 
+  function testRegisterInvalidNamespace() public {
+    bytes14 invalid_namespace = "invld__nmsp";
+    vm.expectRevert(abi.encodeWithSelector(IWorldErrors.World_InvalidNamespace.selector, invalid_namespace));
+    world.registerNamespace(WorldResourceIdLib.encodeNamespace(invalid_namespace));
+  }
+
   function testRegisterCoreNamespacesRevert() public {
     vm.expectRevert(
       abi.encodeWithSelector(

From 0598d1e647e50802287ced99a7c5d7bc7abf79e7 Mon Sep 17 00:00:00 2001
From: alvrs <alvarius@lattice.xyz>
Date: Mon, 22 Jan 2024 17:55:37 +0000
Subject: [PATCH 2/9] update gas-report

---
 packages/world-modules/gas-report.json | 12 ++++++------
 packages/world/gas-report.json         | 10 +++++-----
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/packages/world-modules/gas-report.json b/packages/world-modules/gas-report.json
index a330ba3498..e947939188 100644
--- a/packages/world-modules/gas-report.json
+++ b/packages/world-modules/gas-report.json
@@ -135,7 +135,7 @@
     "file": "test/KeysWithValueModule.t.sol",
     "test": "testGetKeysWithValueGas",
     "name": "install keys with value module",
-    "gasUsed": 683899
+    "gasUsed": 687446
   },
   {
     "file": "test/KeysWithValueModule.t.sol",
@@ -153,7 +153,7 @@
     "file": "test/KeysWithValueModule.t.sol",
     "test": "testInstall",
     "name": "install keys with value module",
-    "gasUsed": 683899
+    "gasUsed": 687446
   },
   {
     "file": "test/KeysWithValueModule.t.sol",
@@ -165,7 +165,7 @@
     "file": "test/KeysWithValueModule.t.sol",
     "test": "testSetAndDeleteRecordHook",
     "name": "install keys with value module",
-    "gasUsed": 683899
+    "gasUsed": 687446
   },
   {
     "file": "test/KeysWithValueModule.t.sol",
@@ -183,7 +183,7 @@
     "file": "test/KeysWithValueModule.t.sol",
     "test": "testSetField",
     "name": "install keys with value module",
-    "gasUsed": 683899
+    "gasUsed": 687446
   },
   {
     "file": "test/KeysWithValueModule.t.sol",
@@ -303,7 +303,7 @@
     "file": "test/UniqueEntityModule.t.sol",
     "test": "testInstall",
     "name": "install unique entity module",
-    "gasUsed": 701756
+    "gasUsed": 705303
   },
   {
     "file": "test/UniqueEntityModule.t.sol",
@@ -315,7 +315,7 @@
     "file": "test/UniqueEntityModule.t.sol",
     "test": "testInstallRoot",
     "name": "installRoot unique entity module",
-    "gasUsed": 670623
+    "gasUsed": 674170
   },
   {
     "file": "test/UniqueEntityModule.t.sol",
diff --git a/packages/world/gas-report.json b/packages/world/gas-report.json
index 3d135987cd..e6ae595a9d 100644
--- a/packages/world/gas-report.json
+++ b/packages/world/gas-report.json
@@ -63,7 +63,7 @@
     "file": "test/Factories.t.sol",
     "test": "testWorldFactory",
     "name": "deploy world via WorldFactory",
-    "gasUsed": 13041829
+    "gasUsed": 13045376
   },
   {
     "file": "test/World.t.sol",
@@ -111,7 +111,7 @@
     "file": "test/World.t.sol",
     "test": "testRegisterNamespace",
     "name": "Register a new namespace",
-    "gasUsed": 120951
+    "gasUsed": 124498
   },
   {
     "file": "test/World.t.sol",
@@ -129,13 +129,13 @@
     "file": "test/World.t.sol",
     "test": "testRegisterTable",
     "name": "Register a new table in the namespace",
-    "gasUsed": 536881
+    "gasUsed": 536849
   },
   {
     "file": "test/World.t.sol",
     "test": "testRenounceNamespace",
     "name": "Renounce namespace ownership",
-    "gasUsed": 36773
+    "gasUsed": 40320
   },
   {
     "file": "test/World.t.sol",
@@ -153,7 +153,7 @@
     "file": "test/World.t.sol",
     "test": "testUnregisterNamespaceDelegation",
     "name": "unregister a namespace delegation",
-    "gasUsed": 28360
+    "gasUsed": 31907
   },
   {
     "file": "test/World.t.sol",

From fbc96a22a73c691e0e66e321883b0a237bc9e970 Mon Sep 17 00:00:00 2001
From: alvrs <alvarius@lattice.xyz>
Date: Mon, 22 Jan 2024 18:31:18 +0000
Subject: [PATCH 3/9] refactor

---
 packages/world-modules/gas-report.json          | 12 ++++++------
 packages/world/gas-report.json                  |  8 ++++----
 .../implementations/AccessManagementSystem.sol  |  8 ++++----
 .../implementations/BalanceTransferSystem.sol   |  6 +++---
 .../implementations/WorldRegistrationSystem.sol | 12 ++++++------
 ...quireNamespace.sol => validateNamespace.sol} | 17 ++++++-----------
 6 files changed, 29 insertions(+), 34 deletions(-)
 rename packages/world/src/{requireNamespace.sol => validateNamespace.sol} (76%)

diff --git a/packages/world-modules/gas-report.json b/packages/world-modules/gas-report.json
index e947939188..310266e60e 100644
--- a/packages/world-modules/gas-report.json
+++ b/packages/world-modules/gas-report.json
@@ -135,7 +135,7 @@
     "file": "test/KeysWithValueModule.t.sol",
     "test": "testGetKeysWithValueGas",
     "name": "install keys with value module",
-    "gasUsed": 687446
+    "gasUsed": 687430
   },
   {
     "file": "test/KeysWithValueModule.t.sol",
@@ -153,7 +153,7 @@
     "file": "test/KeysWithValueModule.t.sol",
     "test": "testInstall",
     "name": "install keys with value module",
-    "gasUsed": 687446
+    "gasUsed": 687430
   },
   {
     "file": "test/KeysWithValueModule.t.sol",
@@ -165,7 +165,7 @@
     "file": "test/KeysWithValueModule.t.sol",
     "test": "testSetAndDeleteRecordHook",
     "name": "install keys with value module",
-    "gasUsed": 687446
+    "gasUsed": 687430
   },
   {
     "file": "test/KeysWithValueModule.t.sol",
@@ -183,7 +183,7 @@
     "file": "test/KeysWithValueModule.t.sol",
     "test": "testSetField",
     "name": "install keys with value module",
-    "gasUsed": 687446
+    "gasUsed": 687430
   },
   {
     "file": "test/KeysWithValueModule.t.sol",
@@ -303,7 +303,7 @@
     "file": "test/UniqueEntityModule.t.sol",
     "test": "testInstall",
     "name": "install unique entity module",
-    "gasUsed": 705303
+    "gasUsed": 705287
   },
   {
     "file": "test/UniqueEntityModule.t.sol",
@@ -315,7 +315,7 @@
     "file": "test/UniqueEntityModule.t.sol",
     "test": "testInstallRoot",
     "name": "installRoot unique entity module",
-    "gasUsed": 674170
+    "gasUsed": 674154
   },
   {
     "file": "test/UniqueEntityModule.t.sol",
diff --git a/packages/world/gas-report.json b/packages/world/gas-report.json
index e6ae595a9d..f180dbc31b 100644
--- a/packages/world/gas-report.json
+++ b/packages/world/gas-report.json
@@ -63,7 +63,7 @@
     "file": "test/Factories.t.sol",
     "test": "testWorldFactory",
     "name": "deploy world via WorldFactory",
-    "gasUsed": 13045376
+    "gasUsed": 13045360
   },
   {
     "file": "test/World.t.sol",
@@ -111,7 +111,7 @@
     "file": "test/World.t.sol",
     "test": "testRegisterNamespace",
     "name": "Register a new namespace",
-    "gasUsed": 124498
+    "gasUsed": 124482
   },
   {
     "file": "test/World.t.sol",
@@ -135,7 +135,7 @@
     "file": "test/World.t.sol",
     "test": "testRenounceNamespace",
     "name": "Renounce namespace ownership",
-    "gasUsed": 40320
+    "gasUsed": 40304
   },
   {
     "file": "test/World.t.sol",
@@ -153,7 +153,7 @@
     "file": "test/World.t.sol",
     "test": "testUnregisterNamespaceDelegation",
     "name": "unregister a namespace delegation",
-    "gasUsed": 31907
+    "gasUsed": 31891
   },
   {
     "file": "test/World.t.sol",
diff --git a/packages/world/src/modules/core/implementations/AccessManagementSystem.sol b/packages/world/src/modules/core/implementations/AccessManagementSystem.sol
index 51816fd70a..1dffc586aa 100644
--- a/packages/world/src/modules/core/implementations/AccessManagementSystem.sol
+++ b/packages/world/src/modules/core/implementations/AccessManagementSystem.sol
@@ -6,7 +6,7 @@ import { AccessControl } from "../../../AccessControl.sol";
 import { ResourceId } from "../../../WorldResourceId.sol";
 import { ResourceAccess } from "../../../codegen/tables/ResourceAccess.sol";
 import { NamespaceOwner } from "../../../codegen/tables/NamespaceOwner.sol";
-import { requireNamespace } from "../../../requireNamespace.sol";
+import { validateNamespace } from "../../../validateNamespace.sol";
 
 import { LimitedCallContext } from "../LimitedCallContext.sol";
 
@@ -53,8 +53,8 @@ contract AccessManagementSystem is System, LimitedCallContext {
    * @param newOwner The address to which ownership should be transferred.
    */
   function transferOwnership(ResourceId namespaceId, address newOwner) public virtual onlyDelegatecall {
-    // Require the namespace ID to be a valid namespace
-    requireNamespace(namespaceId);
+    // Require the namespace to be a valid namespace ID
+    validateNamespace(namespaceId);
 
     // Require the namespace to exist
     AccessControl.requireExistence(namespaceId);
@@ -79,7 +79,7 @@ contract AccessManagementSystem is System, LimitedCallContext {
    */
   function renounceOwnership(ResourceId namespaceId) public virtual onlyDelegatecall {
     // Require the namespace ID to be a valid namespace
-    requireNamespace(namespaceId);
+    validateNamespace(namespaceId);
 
     // Require the namespace to exist
     AccessControl.requireExistence(namespaceId);
diff --git a/packages/world/src/modules/core/implementations/BalanceTransferSystem.sol b/packages/world/src/modules/core/implementations/BalanceTransferSystem.sol
index fa7a30a566..cb703f8bdc 100644
--- a/packages/world/src/modules/core/implementations/BalanceTransferSystem.sol
+++ b/packages/world/src/modules/core/implementations/BalanceTransferSystem.sol
@@ -11,7 +11,7 @@ import { RESOURCE_NAMESPACE } from "../../../worldResourceTypes.sol";
 import { IWorldErrors } from "../../../IWorldErrors.sol";
 
 import { Balances } from "../../../codegen/tables/Balances.sol";
-import { requireNamespace } from "../../../requireNamespace.sol";
+import { validateNamespace } from "../../../validateNamespace.sol";
 
 import { LimitedCallContext } from "../LimitedCallContext.sol";
 
@@ -35,9 +35,9 @@ contract BalanceTransferSystem is System, IWorldErrors, LimitedCallContext {
     uint256 amount
   ) public virtual onlyDelegatecall {
     // Require the from namespace to be a valid namespace ID
-    requireNamespace(fromNamespaceId);
+    validateNamespace(fromNamespaceId);
     // Require the to namespace to be a valid namespace ID
-    requireNamespace(toNamespaceId);
+    validateNamespace(toNamespaceId);
 
     // Require the namespace to exist
     AccessControl.requireExistence(toNamespaceId);
diff --git a/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol b/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol
index f88a6faf68..3112fd4b52 100644
--- a/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol
+++ b/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol
@@ -27,7 +27,7 @@ import { SystemRegistry } from "../../../codegen/tables/SystemRegistry.sol";
 import { Systems } from "../../../codegen/tables/Systems.sol";
 import { FunctionSelectors } from "../../../codegen/tables/FunctionSelectors.sol";
 import { FunctionSignatures } from "../../../codegen/tables/FunctionSignatures.sol";
-import { requireNamespace } from "../../../requireNamespace.sol";
+import { validateNamespace } from "../../../validateNamespace.sol";
 
 import { LimitedCallContext } from "../LimitedCallContext.sol";
 
@@ -44,8 +44,8 @@ contract WorldRegistrationSystem is System, IWorldErrors, LimitedCallContext {
    * @param namespaceId The unique identifier for the new namespace
    */
   function registerNamespace(ResourceId namespaceId) public virtual onlyDelegatecall {
-    // Require namespace ID to be a valid namespace
-    requireNamespace(namespaceId);
+    // Require namespace to be a valid namespace ID
+    validateNamespace(namespaceId);
 
     // Require namespace to not exist yet
     if (ResourceIds._getExists(namespaceId)) {
@@ -299,8 +299,8 @@ contract WorldRegistrationSystem is System, IWorldErrors, LimitedCallContext {
     ResourceId delegationControlId,
     bytes memory initCallData
   ) public onlyDelegatecall {
-    // Require namespace ID to be a valid namespace
-    requireNamespace(namespaceId);
+    // Require namespace to be a valid namespace ID
+    validateNamespace(namespaceId);
 
     // Require the delegation to not be unlimited
     if (!Delegation.isLimited(delegationControlId)) {
@@ -335,7 +335,7 @@ contract WorldRegistrationSystem is System, IWorldErrors, LimitedCallContext {
    */
   function unregisterNamespaceDelegation(ResourceId namespaceId) public onlyDelegatecall {
     // Require namespace ID to be a valid namespace
-    requireNamespace(namespaceId);
+    validateNamespace(namespaceId);
 
     // Require the namespace to exist
     AccessControl.requireExistence(namespaceId);
diff --git a/packages/world/src/requireNamespace.sol b/packages/world/src/validateNamespace.sol
similarity index 76%
rename from packages/world/src/requireNamespace.sol
rename to packages/world/src/validateNamespace.sol
index dd5e78c361..bb6f4627e0 100644
--- a/packages/world/src/requireNamespace.sol
+++ b/packages/world/src/validateNamespace.sol
@@ -10,24 +10,19 @@ import { IWorldErrors } from "./IWorldErrors.sol";
 using WorldResourceIdInstance for ResourceId;
 
 /**
- * @notice Checks if a given `resourceId` is a namespace.
+ * @notice Checks if a given `resourceId` is a valid namespace.
  * @dev Reverts with IWorldErrors.World_InvalidResourceType if the ID does not have the correct components.
+ * @dev Reverts with IWorldErrors.World_InvalidNamespace if the namespace includes the reserved separator string ("__").
  * @param resourceId The resource ID to verify.
  */
-function requireNamespace(ResourceId resourceId) pure {
-  requireValidCharacters(resourceId.getNamespace());
-
+function validateNamespace(ResourceId resourceId) pure {
+  // Require the resourceId to have the namespace type
   if (ResourceId.unwrap(resourceId) != ResourceId.unwrap(resourceId.getNamespaceId())) {
     revert IWorldErrors.World_InvalidResourceType(RESOURCE_NAMESPACE, resourceId, resourceId.toString());
   }
-}
 
-/**
- * @notice Checks if a given namespace string is valid.
- * @dev Reverts with IWorldErrors.World_InvalidNamespace if the namespace includes the reserved separator string ("__").
- * @param namespace The namespace to verify.
- */
-function requireValidCharacters(bytes14 namespace) pure {
+  // Require the namespace to not include the reserved separator
+  bytes14 namespace = resourceId.getNamespace();
   for (uint256 i; i < NAMESPACE_BYTES - 1; i++) {
     if (Bytes.slice1(namespace, i) == bytes1("_") && Bytes.slice1(namespace, i + 1) == bytes1("_")) {
       revert IWorldErrors.World_InvalidNamespace(namespace);

From df61c19e91e84f14f5223f4a560daee745852749 Mon Sep 17 00:00:00 2001
From: alvrs <alvarius@lattice.xyz>
Date: Mon, 22 Jan 2024 18:46:45 +0000
Subject: [PATCH 4/9] add additional test

---
 packages/world/test/World.t.sol | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/packages/world/test/World.t.sol b/packages/world/test/World.t.sol
index 9090eca6e6..278733ed46 100644
--- a/packages/world/test/World.t.sol
+++ b/packages/world/test/World.t.sol
@@ -349,9 +349,20 @@ contract WorldTest is Test, GasReporter {
   }
 
   function testRegisterInvalidNamespace() public {
-    bytes14 invalid_namespace = "invld__nmsp";
-    vm.expectRevert(abi.encodeWithSelector(IWorldErrors.World_InvalidNamespace.selector, invalid_namespace));
-    world.registerNamespace(WorldResourceIdLib.encodeNamespace(invalid_namespace));
+    ResourceId invalidNamespaceId = WorldResourceIdLib.encode(RESOURCE_SYSTEM, "namespace", "system");
+    vm.expectRevert(
+      abi.encodeWithSelector(
+        IWorldErrors.World_InvalidResourceType.selector,
+        RESOURCE_NAMESPACE,
+        invalidNamespaceId,
+        invalidNamespaceId.toString()
+      )
+    );
+    world.registerNamespace(invalidNamespaceId);
+
+    bytes14 invalidNamespace = "invld__nmsp";
+    vm.expectRevert(abi.encodeWithSelector(IWorldErrors.World_InvalidNamespace.selector, invalidNamespace));
+    world.registerNamespace(WorldResourceIdLib.encodeNamespace(invalidNamespace));
   }
 
   function testRegisterCoreNamespacesRevert() public {

From edeea8634218d6c677f86131d314a8b1d899fa40 Mon Sep 17 00:00:00 2001
From: alvarius <alvarius@lattice.xyz>
Date: Mon, 22 Jan 2024 18:56:59 +0000
Subject: [PATCH 5/9] Create tidy-stingrays-think.md

---
 .changeset/tidy-stingrays-think.md | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 .changeset/tidy-stingrays-think.md

diff --git a/.changeset/tidy-stingrays-think.md b/.changeset/tidy-stingrays-think.md
new file mode 100644
index 0000000000..f1b5d8ecf8
--- /dev/null
+++ b/.changeset/tidy-stingrays-think.md
@@ -0,0 +1,9 @@
+---
+"@latticexyz/world": major
+---
+
+Namespaces are not allowed to contain double underscores ("__") anymore, as this sequence of characters is used to [separate the namespace and function selector](https://github.com/latticexyz/mud/pull/2168) in namespaced systems.
+This is to prevent signature clashes of functions in different namespaces.
+
+(Example: If namespaces were allowed to contain this separator string, a function "function" in namespace "namespace__my" would result in the namespaced function selector "namespace__my__function",
+and would clash with a function "my__function" in namespace "namespace".)

From 3630aba5366bcaf404842d68ba7a906ff01fd8d3 Mon Sep 17 00:00:00 2001
From: alvrs <alvarius@lattice.xyz>
Date: Mon, 22 Jan 2024 20:16:34 +0000
Subject: [PATCH 6/9] prettier

---
 .changeset/tidy-stingrays-think.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.changeset/tidy-stingrays-think.md b/.changeset/tidy-stingrays-think.md
index f1b5d8ecf8..97a4431ba3 100644
--- a/.changeset/tidy-stingrays-think.md
+++ b/.changeset/tidy-stingrays-think.md
@@ -2,8 +2,8 @@
 "@latticexyz/world": major
 ---
 
-Namespaces are not allowed to contain double underscores ("__") anymore, as this sequence of characters is used to [separate the namespace and function selector](https://github.com/latticexyz/mud/pull/2168) in namespaced systems.
+Namespaces are not allowed to contain double underscores ("\_\_") anymore, as this sequence of characters is used to [separate the namespace and function selector](https://github.com/latticexyz/mud/pull/2168) in namespaced systems.
 This is to prevent signature clashes of functions in different namespaces.
 
-(Example: If namespaces were allowed to contain this separator string, a function "function" in namespace "namespace__my" would result in the namespaced function selector "namespace__my__function",
-and would clash with a function "my__function" in namespace "namespace".)
+(Example: If namespaces were allowed to contain this separator string, a function "function" in namespace "namespace**my" would result in the namespaced function selector "namespace**my**function",
+and would clash with a function "my**function" in namespace "namespace".)

From c97adb64e6edd271e4f6f59fafbb4bfe3aca1ba9 Mon Sep 17 00:00:00 2001
From: alvarius <alvarius@lattice.xyz>
Date: Mon, 22 Jan 2024 20:49:11 +0000
Subject: [PATCH 7/9] Apply suggestions from code review

---
 .changeset/tidy-stingrays-think.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.changeset/tidy-stingrays-think.md b/.changeset/tidy-stingrays-think.md
index 97a4431ba3..2bbee42817 100644
--- a/.changeset/tidy-stingrays-think.md
+++ b/.changeset/tidy-stingrays-think.md
@@ -5,5 +5,5 @@
 Namespaces are not allowed to contain double underscores ("\_\_") anymore, as this sequence of characters is used to [separate the namespace and function selector](https://github.com/latticexyz/mud/pull/2168) in namespaced systems.
 This is to prevent signature clashes of functions in different namespaces.
 
-(Example: If namespaces were allowed to contain this separator string, a function "function" in namespace "namespace**my" would result in the namespaced function selector "namespace**my**function",
-and would clash with a function "my**function" in namespace "namespace".)
+(Example: If namespaces were allowed to contain this separator string, a function "function" in namespace "namespace\_\_my" would result in the namespaced function selector "namespace\_\_my\_\_function",
+and would clash with a function "my\_\_function" in namespace "namespace".)

From f3bbc32db91612c07e97dec51246a617d452a808 Mon Sep 17 00:00:00 2001
From: alvarius <alvarius@lattice.xyz>
Date: Mon, 22 Jan 2024 20:52:14 +0000
Subject: [PATCH 8/9] Apply suggestions from code review

---
 .../modules/core/implementations/AccessManagementSystem.sol   | 2 +-
 .../modules/core/implementations/WorldRegistrationSystem.sol  | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/world/src/modules/core/implementations/AccessManagementSystem.sol b/packages/world/src/modules/core/implementations/AccessManagementSystem.sol
index 1dffc586aa..41e58ad6af 100644
--- a/packages/world/src/modules/core/implementations/AccessManagementSystem.sol
+++ b/packages/world/src/modules/core/implementations/AccessManagementSystem.sol
@@ -53,7 +53,7 @@ contract AccessManagementSystem is System, LimitedCallContext {
    * @param newOwner The address to which ownership should be transferred.
    */
   function transferOwnership(ResourceId namespaceId, address newOwner) public virtual onlyDelegatecall {
-    // Require the namespace to be a valid namespace ID
+    // Require the namespace ID to be a valid namespace
     validateNamespace(namespaceId);
 
     // Require the namespace to exist
diff --git a/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol b/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol
index 3112fd4b52..77fecb482a 100644
--- a/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol
+++ b/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol
@@ -44,7 +44,7 @@ contract WorldRegistrationSystem is System, IWorldErrors, LimitedCallContext {
    * @param namespaceId The unique identifier for the new namespace
    */
   function registerNamespace(ResourceId namespaceId) public virtual onlyDelegatecall {
-    // Require namespace to be a valid namespace ID
+    // Require namespace ID to be valid namespace
     validateNamespace(namespaceId);
 
     // Require namespace to not exist yet
@@ -299,7 +299,7 @@ contract WorldRegistrationSystem is System, IWorldErrors, LimitedCallContext {
     ResourceId delegationControlId,
     bytes memory initCallData
   ) public onlyDelegatecall {
-    // Require namespace to be a valid namespace ID
+    // Require namespace ID to be a valid namespace
     validateNamespace(namespaceId);
 
     // Require the delegation to not be unlimited

From e5372ab3912cfcff36ce4a7a3e2a125b578b131b Mon Sep 17 00:00:00 2001
From: alvarius <alvarius@lattice.xyz>
Date: Mon, 22 Jan 2024 20:52:46 +0000
Subject: [PATCH 9/9] Update
 packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol

---
 .../modules/core/implementations/WorldRegistrationSystem.sol    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol b/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol
index 77fecb482a..a0f7dc70dc 100644
--- a/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol
+++ b/packages/world/src/modules/core/implementations/WorldRegistrationSystem.sol
@@ -44,7 +44,7 @@ contract WorldRegistrationSystem is System, IWorldErrors, LimitedCallContext {
    * @param namespaceId The unique identifier for the new namespace
    */
   function registerNamespace(ResourceId namespaceId) public virtual onlyDelegatecall {
-    // Require namespace ID to be valid namespace
+    // Require namespace ID to be a valid namespace
     validateNamespace(namespaceId);
 
     // Require namespace to not exist yet