Specify replacement behaviour when replaceable events have the same timestamp

- This is so that relays can converge on a deterministic sets of events, no matter the order they were received
- Otherwise, clients or relays that sync their sets of events could continually retransmit events they think are missing on the other side, wasting bandwidth

1 files changed, 2 insertions, 0 deletions

diff --git a/16.md b/16.md
index 4d9481d..8ef4af4 100644
--- a/16.md
+++ b/16.md
@@ -20,6 +20,8 @@ Upon a replaceable event with a newer timestamp than the currently known latest
 effectively replacing what gets returned when querying for
 `author:kind` tuples.
 
+If two events have the same timestamp, the event with the lowest id (first in lexical order) SHOULD be retained, and the other discarded.
+
 Ephemeral Events
 ----------------
 An *ephemeral event* is defined as an event with a kind `20000 <= n < 30000`.