diff --git a/p4.md b/p4.md
index b30f641d4c3fe314df32eaea861a9b3fb5ef33b7..32c41dc8d41ef89008e4973558e787754e00a1a6 100644
--- a/p4.md
+++ b/p4.md
@@ -176,6 +176,12 @@ Note that this is show counts of blobs and RPCs used for each pull
 request, though the video does not. Yours should do this.
 
 ### Server command line args:
+- **-s <serverport>** : Bare integer.
+- **-S <serv1:port1,serv2:port2...>** : Comma-separated list of
+		<servname:portno>. If specified, this takes precendence over
+		anything `compose.yaml` says. Intended for use in local
+		debugging, whereas the server names from `compose.yaml` are
+		used in the containerization test.
 - **-p <period>**: Changes the anti-entropy period.
 - **-a**: The code you use to implement *pull* requests should spin
   off new gothreads to handle *path* and *get* calls in parallel. This