diff --git a/protocol/README.md b/protocol/README.md
index 147d4c2..c6c44d4 100644
--- a/protocol/README.md
+++ b/protocol/README.md
@@ -39,17 +39,26 @@ Codes in [errors.json](errors.json) fall into these ranges:
 | 80000 | connection-related |
 | 90000 | channel-related |
 
-Codes from `100000` are defined outside of scope of this repository.
-In other words, these higher ranges are reserved for use by specific Ably projects and ecosystems, where these codes are unknown to the core Ably service:
+Codes above `100000` are reserved for use by specific Ably projects and ecosystems, where these codes are unknown to the core Ably service. Definitions for these ranges are defined below.
 
-| From | To | Project / Ecosystem | Location of Definitions |
-| ---- | -- | ------------------- | ----------------------- |
-| 100000 | 100999 | Asset Tracking | [Specification: Error codes](https://github.com/ably/ably-asset-tracking-common/tree/main/specification#error-codes) |
+#### Asset Tracking
 
-The table above is our canonical location for:
+Codes for Asset Tracking are maintained externally.
 
-- specifying these ranges
-- delegating the definitions of codes that sit within these ranges to elsewhere
+| From | To | Location of Definitions |
+| ---- | -- | ----------------------- |
+| 100000 | 100999 | [Specification: Error codes](https://github.com/ably/ably-asset-tracking-common/tree/main/specification#error-codes) |
+
+#### Spaces
+
+| From  | Title |
+| ----- | ----- |
+| 101000 | Space name missing |
+| 101001 | Not entered space  |
+| 101002 | Lock request exists |
+| 101003 | Lock is locked |
+| 101004 | Lock invalidated |
+| 101005 | Lock released |
 
 ## Agents
 
diff --git a/protocol/errors.json b/protocol/errors.json
index 3671fd5..ecf3ea9 100644
--- a/protocol/errors.json
+++ b/protocol/errors.json
@@ -167,5 +167,12 @@
   "91003": "unable to enter presence channel (maximum member limit exceeded)",
   "91004": "unable to automatically re-enter presence channel",
   "91005": "presence state is out of sync",
-  "91100": "member implicitly left presence channel (connection closed)"
+  "91100": "member implicitly left presence channel (connection closed)",
+
+  "101000": "must have a non-empty name for the space",
+  "101001": "must enter a space to perform this operation",
+  "101002": "lock request already exists",
+  "101003": "lock is currently locked",
+  "101004": "lock was invalidated by a concurrent lock request which now holds the lock",
+  "101005": "lock was released"
 }
diff --git a/protocol/errorsHelp.json b/protocol/errorsHelp.json
index 2a47f85..6428622 100644
--- a/protocol/errorsHelp.json
+++ b/protocol/errorsHelp.json
@@ -66,5 +66,12 @@
   "91000": "https://faqs.ably.com/error-code-91000",
   "91001": "https://faqs.ably.com/error-code-91001",
   "91003": "https://faqs.ably.com/error-91003-maximum-member-limit-exceeded",
-  "91005": "https://faqs.ably.com/error-code-91005"
+  "91005": "https://faqs.ably.com/error-code-91005",
+
+  "101000": "https://faqs.ably.com/error-code-101000",
+  "101001": "https://faqs.ably.com/error-code-101001",
+  "101002": "https://faqs.ably.com/error-code-101002",
+  "101003": "https://faqs.ably.com/error-code-101003",
+  "101004": "https://faqs.ably.com/error-code-101004",
+  "101004": "https://faqs.ably.com/error-code-101005"
 }