diff --git a/01.md b/01.md
index 4b33975..6369743 100644
--- a/01.md
+++ b/01.md
@@ -80,10 +80,12 @@ Kinds specify how clients should interpret the meaning of each event and the oth
 And also a convention for kind ranges that allow for easier experimentation and flexibility of relay implementation:
 
 - for kind `n` such that `1000 <= n < 10000`, events are **regular**, which means they're all expected to be stored by relays.
-- for kind `n` such that `10000 <= n < 20000`, events are **replaceable**, which means that, for each combination of `pubkey` and `kind`, only the latest event is expected to be stored by relays, older versions are expected to be discarded.
+- for kind `n` such that `10000 <= n < 20000 || k == 0 || k == 3`, events are **replaceable**, which means that, for each combination of `pubkey` and `kind`, only the latest event is expected to be stored by relays, older versions are expected to be discarded.
 - for kind `n` such that `20000 <= n < 30000`, events are **ephemeral**, which means they are not expected to be stored by relays.
 - for kind `n` such that `30000 <= n < 40000`, events are **parameterized replaceable**, which means that, for each combination of `pubkey`, `kind` and the `d` tag, only the latest event is expected to be stored by relays, older versions are expected to be discarded.
 
+In case of replaceable events with the same timestamp, the event with the lowest id (first in lexical order) should be retained, and the other discarded.
+
 These are just conventions and relay implementations may differ.
 
 ## Communication between clients and relays