diff --git a/book/art/runtime.bob b/book/art/runtime.bob
index a483a7d7e..b247f458b 100644
--- a/book/art/runtime.bob
+++ b/book/art/runtime.bob
@@ -3,7 +3,7 @@
 | sigverify +--->| lock memory +--->| validate fee +--->| allocate accounts  +--->
 `-----------`    `-------------`    `--------------`    `--------------------`    
                                 
-    .------------.    .---------.    .--------------.   .--------------.
---->| load data  +--->| execute +--->| commit data  +-->|unlock memory |
-    `------------`    `---------`    `--------------`   `--------------`
+    .------------.    .---------.    .--------.    .--------------.   .--------------.
+--->| load data  +--->| execute +--->| record +--->| commit data  +-->|unlock memory |
+    `------------`    `---------`    `--------`    `--------------`   `--------------`
 
diff --git a/book/src/runtime.md b/book/src/runtime.md
index 1fefc7a6b..0881a5bfc 100644
--- a/book/src/runtime.md
+++ b/book/src/runtime.md
@@ -44,6 +44,10 @@ The runtime enforces the following rules:
    greater than or equal to the balances before the transaction.
 4. All instructions in the transaction executed atomically. If one fails, all
    account modifications are discarded.
+5. Before committing the accounts, the transactions are tagged with a count
+   from the PoH service, indicating the time transaction processing completed.
+   If that time falls outside the leader's allotted slot, the transactions
+   are discarded.
 
 Execution of the program involves mapping the program's public key to an
 entrypoint which takes a pointer to the transaction, and an array of loaded