diff --git a/README.md b/README.md
index c280494..f8fa680 100644
--- a/README.md
+++ b/README.md
@@ -18,3 +18,7 @@ The following files are **required** for system activation:
 - /persist/home/${mainUser}/.ssh/id_ed25519
 
 This private key will be used by sops-nix to decrypt the secrets in [[secrets/secrets.yaml]]. The secrets inside the yaml file should also be set, or otherwise removed alongside their declarations (in [[modules/nixos/system/secrets.nix]]) and references.
+
+# Impermanence
+
+System and user state is stored under /persist. Anything not declared under `{environment,home}.persistence` is deleted on system boot.