diff --git a/src/restore.sh b/src/restore.sh
index 23b1e92..6340645 100644
--- a/src/restore.sh
+++ b/src/restore.sh
@@ -1,6 +1,6 @@
 #! /bin/sh
 
-set -u
+set -u # `-e` omitted intentionally, but i can't remember why exactly :'(
 set -o pipefail
 
 if [ -z "$S3_BUCKET" ]; then
@@ -14,7 +14,7 @@ if [ -z "$POSTGRES_DATABASE" ]; then
 fi
 
 if [ -z "$POSTGRES_HOST" ]; then
-  # TODO: what is this?
+  # https://docs.docker.com/network/links/#environment-variables
   if [ -n "$POSTGRES_PORT_5432_TCP_ADDR" ]; then
     POSTGRES_HOST=$POSTGRES_PORT_5432_TCP_ADDR
     POSTGRES_PORT=$POSTGRES_PORT_5432_TCP_PORT