diff --git a/roles/nginx/templates/https.j2 b/roles/nginx/templates/https.j2
index 154f957..29ac0f2 100644
--- a/roles/nginx/templates/https.j2
+++ b/roles/nginx/templates/https.j2
@@ -1,3 +1,4 @@
+{# helper variables and per-site defaults that we can't set in role defaults #}
 {% set domain_name       = item.nginx_domain_name %}
 {# assume HSTS is off unless a vhost explicitly sets it to "yes" #}
 {% set enable_hsts       = item.nginx_enable_hsts | default("no") %}
diff --git a/roles/nginx/templates/vhost.conf.j2 b/roles/nginx/templates/vhost.conf.j2
index 4f424c3..8268ddc 100644
--- a/roles/nginx/templates/vhost.conf.j2
+++ b/roles/nginx/templates/vhost.conf.j2
@@ -1,3 +1,4 @@
+{# helper variables and per-site defaults that we can't set in role defaults #}
 {% set domain_name    = item.nginx_domain_name %}
 {% set domain_aliases = item.nginx_domain_aliases | default("") %}
 {% set enable_https   = item.nginx_enable_https | default("no") %}