diff --git a/README.md b/README.md
index bc4ba100b..b5a898d37 100644
--- a/README.md
+++ b/README.md
@@ -45,6 +45,7 @@ The merge is still actively in development. The exact specification has not been
   * [Merge fork](specs/merge/fork.md)
   * [Fork Choice changes](specs/merge/fork-choice.md)
   * [Validator additions](specs/merge/validator.md)
+  * [Client settings](specs/merge/client_settings.md)
 
 ### Sharding
 
@@ -53,7 +54,7 @@ Sharding follows the merge, and is divided into three parts:
 * Sharding base functionality - In early engineering phase
   * [Beacon Chain changes](specs/sharding/beacon-chain.md)
   * [P2P Network changes](specs/sharding/p2p-interface.md)
-* Custody Game - Ready, dependent on sharding 
+* Custody Game - Ready, dependent on sharding
   * [Beacon Chain changes](specs/custody_game/beacon-chain.md)
   * [Validator custody work](specs/custody_game/validator.md)
 * Data Availability Sampling - In active R&D
diff --git a/specs/merge/client_settings.md b/specs/merge/client_settings.md
new file mode 100644
index 000000000..172617a74
--- /dev/null
+++ b/specs/merge/client_settings.md
@@ -0,0 +1,14 @@
+# The Merge -- Client Settings
+
+**Notice**: This document is a work-in-progress for researchers and implementers.
+
+This document specifies configurable settings that merge clients are expected to ship with.
+
+### Override terminal total difficulty
+
+To coordinate changes to [`terminal_total_difficulty`](specs/merge/fork-choice.md#transitionstore), clients
+should have a setting `--terminal-total-difficulty-override`.
+
+If `TransitionStore` has already been initialized, this just changes the value of
+`TransitionStore.terminal_total_difficulty`, otherwise it initializes `TransitionStore` with the specified
+`terminal_total_difficulty`.