diff --git a/server/sql/001-schema.sql b/server/sql/001-schema.sql
index 6890fe2..8332ab1 100644
--- a/server/sql/001-schema.sql
+++ b/server/sql/001-schema.sql
@@ -15,7 +15,9 @@ CREATE TABLE IF NOT EXISTS sync_row (
   tbl         TEXT        NOT NULL,
   pk          TEXT        NOT NULL,
   data        JSONB       NOT NULL,
-  -- The client's wall clock, and the field last-write-wins compares.
+  -- The client's wall clock, when the row was last edited. Kept for display
+  -- only: since protocol 2 (002-protocol-2.sql) nothing compares it — a
+  -- write is decided by change_seq alone.
   updated_at  BIGINT      NOT NULL,
   -- A delete. Kept as a row so it can be handed to a device that was
   -- offline when it happened.